Hi,
the suggested solution did not work for me.
Instead I ran the following:
debootstrap --no-check-gpg --no-check-certificate --include univention-kernel-image --arch amd64 ucs445 /mnt/deboot http://updates.software-univention.de/4.4/maintained/4.4-5/
Then I booted this and set the apt source:
cat <<E_O_APT >/etc/apt/sources.list
deb http://updates.software-univention.de/4.0/maintained/ 4.0-0/all/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-0/amd64/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-1/all/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-1/amd64/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-2/all/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-2/amd64/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-3/all/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-3/amd64/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-4/all/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-4/amd64/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-5/all/
deb http://updates.software-univention.de/4.0/maintained/ 4.0-5/amd64/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-0/all/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-0/amd64/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-1/all/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-1/amd64/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-2/all/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-2/amd64/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-3/all/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-3/amd64/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-4/all/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-4/amd64/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-5/all/
deb http://updates.software-univention.de/4.1/maintained/ 4.1-5/amd64/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-0/all/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-0/amd64/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-1/all/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-1/amd64/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-2/all/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-2/amd64/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-3/all/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-3/amd64/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-4/all/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-4/amd64/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-5/all/
deb http://updates.software-univention.de/4.2/maintained/ 4.2-5/amd64/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-0/all/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-0/amd64/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-1/all/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-1/amd64/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-2/all/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-2/amd64/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-3/all/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-3/amd64/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-4/all/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-4/amd64/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-5/all/
deb http://updates.software-univention.de/4.3/maintained/ 4.3-5/amd64/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-0/all/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-0/amd64/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-1/all/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-1/amd64/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-2/all/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-2/amd64/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-3/all/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-3/amd64/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-4/all/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-4/amd64/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-5/all/
deb http://updates.software-univention.de/4.4/maintained/ 4.4-5/amd64/
E_O_APT
cat <<E_O_APT > /etc/apt/mirror.list
set nthreads 10
set recreate_packages no
E_O_APT
Finally, you are able to install everything needed to get the UCS 4.4-5 setup wizzard:
apt-get update
apt-get install -yy univention-welcome-screen acl adduser adwaita-icon-theme amd64-microcode apache2 apache2-bin apache2-data apache2-utils apt apt-transport-https apt-utils at base-files base-passwd bash bash-completion bind9 bind9-host bind9utils binutils bridge-utils bsdmainutils bsdutils busybox bzip2 ca-certificates cgroupfs-mount console-data console-setup console-setup-linux containerd coreutils cpio cpp cpp-6 cracklib-runtime cron curl cy2-saml dash dbus dbus-x11 dconf-gsettings-backend:amd64 dconf-service debconf debconf-i18n debian-archive-keyring debianutils dh-python diffutils dirmngr discover discover-data distro-info-data dkms dmeventd dmidecode dmsetup dnsutils docker-compose docker.io docutils-common dpkg e2fslibs:amd64 e2fsprogs eject emacs24 emacs24-bin-common emacs24-common emacsen-common fakeroot file findutils firefox-esr firmware-amd-graphics firmware-atheros firmware-bnx2 firmware-bnx2x firmware-brcm80211 firmware-cavium firmware-intelwimax firmware-iwlwifi firmware-libertas firmware-linux firmware-linux-free firmware-linux-nonfree firmware-misc-nonfree firmware-myricom firmware-netxen firmware-qlogic firmware-realtek firmware-ti-connectivity fontconfig fontconfig-config fonts-dejavu-core gcc gcc-6 gcc-6-base:amd64 gconf-service gconf2-common gettext-base glib-networking:amd64 glib-networking-common glib-networking-services gnupg gnupg-agent gnutls-bin golang-docker-credential-helpers gpgv grep grub-common grub-pc grub-pc-bin grub2-common gsettings-desktop-schemas gtk-update-icon-cache gzip heimdal-clients hicolor-icon-theme hostname ifenslave ifplugd ifupdown imagemagick-6-common init init-system-helpers initramfs-tools initramfs-tools-core installation-report intel-microcode iproute2 iptables iputils-ping isc-dhcp-client isc-dhcp-common iso-codes iucode-tool kbd keyboard-configuration klibc-utils kmod krb5-config laptop-detect ldap-utils less libacl1:amd64 libapache2-mod-authnz-pam libapparmor1:amd64 libapr1:amd64 libaprutil1:amd64 libaprutil1-dbd-sqlite3:amd64 libaprutil1-ldap:amd64 libapt-inst1.5:amd64 libapt-inst2.0:amd64 libapt-pkg4.12:amd64 libapt-pkg5.0:amd64 libarchive13:amd64 libasan3:amd64 libasn1-8-heimdal:amd64 libasound2:amd64 libasound2-data libassuan0:amd64 libatk-bridge2.0-0:amd64 libatk1.0-0:amd64 libatk1.0-data libatomic1:amd64 libatspi2.0-0:amd64 libattr1:amd64 libaudit-common libaudit1:amd64 libavahi-client3:amd64 libavahi-common-data:amd64 libavahi-common3:amd64 libavcodec57:amd64 libavutil55:amd64 libbind9-140:amd64 libblas-common libblas3 libblkid1:amd64 libboost-iostreams1.49.0 libboost-iostreams1.55.0:amd64 libbsd0:amd64 libbytes-random-secure-perl libbz2-1.0:amd64 libc-bin libc-dev-bin libc-l10n libc6:amd64 libc6-dev:amd64 libcairo-gobject2:amd64 libcairo2:amd64 libcap-ng0:amd64 libcap2:amd64 libcap2-bin libcc1-0:amd64 libcilkrts5:amd64 libcolord2:amd64 libcomerr2:amd64 libcrack2:amd64 libcroco3:amd64 libcrypt-passwdmd5-perl libcrypt-random-seed-perl libcryptsetup4:amd64 libcrystalhd3:amd64 libcups2:amd64 libcupsfilters1:amd64 libcupsimage2:amd64 libcurl3:amd64 libcurl3-gnutls:amd64 libdaemon0:amd64 libdatrie1:amd64 libdb5.3:amd64 libdbi1:amd64 libdbus-1-3:amd64 libdbus-glib-1-2:amd64 libdconf1:amd64 libdebconfclient0:amd64 libdevmapper-event1.02.1:amd64 libdevmapper1.02.1:amd64 libdiscover2 libdns-export162 libdns162:amd64 libdrm-amdgpu1:amd64 libdrm-intel1:amd64 libdrm-nouveau2:amd64 libdrm-radeon1:amd64 libdrm2:amd64 libedit2:amd64 libegl1-mesa:amd64 libelf1:amd64 libenca0:amd64 libepoxy0:amd64 libestr0 libevdev2:amd64 libexempi3:amd64 libexif12:amd64 libexpat1:amd64 libfakeroot:amd64 libfastjson4:amd64 libfdisk1:amd64 libffi6:amd64 libfftw3-double3:amd64 libfile-copy-recursive-perl libfontconfig1:amd64 libfontenc1:amd64 libfreetype6:amd64 libfribidi0:amd64 libfsplib0 libfuse2:amd64 libgbm1:amd64 libgcc-6-dev:amd64 libgcc1:amd64 libgconf-2-4:amd64 libgcrypt20:amd64 libgd3:amd64 libgdbm3:amd64 libgdk-pixbuf2.0-0:amd64 libgdk-pixbuf2.0-common libgeoip1:amd64 libgfortran3:amd64 libgif7:amd64 libgl1-mesa-dri:amd64 libgl1-mesa-glx:amd64 libglapi-mesa:amd64 libglib2.0-0:amd64 libgmp10:amd64 libgnutls-dane0:amd64 libgnutls30:amd64 libgomp1:amd64 libgpg-error0:amd64 libgpm2:amd64 libgraphite2-3:amd64 libgs9:amd64 libgs9-common libgsm1:amd64 libgssapi-krb5-2:amd64 libgssapi3-heimdal:amd64 libgtk-3-0:amd64 libgtk-3-common libgudev-1.0-0:amd64 libharfbuzz0b:amd64 libhcrypto4-heimdal:amd64 libhdb9-heimdal:amd64 libheimbase1-heimdal:amd64 libheimntlm0-heimdal:amd64 libhogweed4:amd64 libhx509-5-heimdal:amd64 libice6:amd64 libicu57:amd64 libid3tag0:amd64 libidn11:amd64 libidn2-0:amd64 libijs-0.35:amd64 libimlib2:amd64 libinput-bin libinput10:amd64 libio-socket-inet6-perl libip4tc0:amd64 libip6tc0:amd64 libiptc0:amd64 libiptcdata0 libirs141:amd64 libisc-export160 libisc160:amd64 libisccc140:amd64 libisccfg140:amd64 libisl15:amd64 libitm1:amd64 libjansson4:amd64 libjbig0:amd64 libjbig2dec0:amd64 libjpeg62-turbo:amd64 libjs-jquery libjs-sphinxdoc libjs-underscore libjson-c2:amd64 libjson-glib-1.0-0:amd64 libjson-glib-1.0-common libjsoncpp1:amd64 libk5crypto3:amd64 libkadm5clnt7-heimdal:amd64 libkadm5srv8-heimdal:amd64 libkafs0-heimdal:amd64 libkdc2-heimdal:amd64 libkeyutils1:amd64 libklibc libkmod2:amd64 libkrb5-26-heimdal:amd64 libkrb5-3:amd64 libkrb5support0:amd64 libksba8:amd64 liblasso3 liblcms2-2:amd64 libldap-2.4-2:amd64 libldap-common libldb1:amd64 liblinear3:amd64 libllvm3.9:amd64 liblmdb0:amd64 liblocale-gettext-perl liblockfile-bin liblockfile1:amd64 liblogging-stdlog0:amd64 liblognorm1:amd64 liblognorm5:amd64 liblqr-1-0:amd64 liblsan0:amd64 libltdl7:amd64 liblua5.1-0:amd64 liblua5.2-0:amd64 liblua5.3-0:amd64 liblvm2app2.2:amd64 liblvm2cmd2.02:amd64 liblwres141:amd64 liblz4-1:amd64 liblzma5:amd64 liblzo2-2:amd64 libm17n-0:amd64 libmagic-mgc libmagic1:amd64 libmagickcore-6.q16-3:amd64 libmagickwand-6.q16-3:amd64 libmariadbclient18:amd64 libmath-random-isaac-perl libmcrypt4 libmnl0:amd64 libmount1:amd64 libmp3lame0:amd64 libmpc3:amd64 libmpdec2:amd64 libmpfr4:amd64 libmpx2:amd64 libmtdev1:amd64 libncurses5:amd64 libncursesw5:amd64 libnet-snmp-perl libnetfilter-conntrack3:amd64 libnetpbm10 libnettle6:amd64 libnewt0.52:amd64 libnfnetlink0:amd64 libnfsidmap2:amd64 libnghttp2-14:amd64 libnl-3-200:amd64 libnl-genl-3-200:amd64 libnpth0:amd64 libnss-extrausers libnss-ldap:amd64 libnuma1:amd64 libobrender32v5 libobt2v5 libodbc1:amd64 libogg0:amd64 libopenjp2-7:amd64 libopts25:amd64 libopus0:amd64 libotf0:amd64 libotp0-heimdal:amd64 libp11-kit0:amd64 libpam-cap:amd64 libpam-cracklib:amd64 libpam-heimdal:amd64 libpam-ldap:amd64 libpam-modules:amd64 libpam-modules-bin libpam-runtime libpam-systemd:amd64 libpam0g:amd64 libpango-1.0-0:amd64 libpangocairo-1.0-0:amd64 libpangoft2-1.0-0:amd64 libpangoxft-1.0-0:amd64 libpaper-utils libpaper1:amd64 libpcap0.8:amd64 libpci3:amd64 libpciaccess0:amd64 libpcre3:amd64 libperl5.24:amd64 libpipeline1:amd64 libpixman-1-0:amd64 libplymouth4:amd64 libpng16-16:amd64 libpopt0:amd64 libpq5:amd64 libprocps0:amd64 libprocps3:amd64 libprocps6:amd64 libproxy1v5:amd64 libpsl5:amd64 libpython-stdlib:amd64 libpython2.7:amd64 libpython2.7-minimal:amd64 libpython2.7-stdlib:amd64 libpython3-stdlib:amd64 libpython3.5-minimal:amd64 libpython3.5-stdlib:amd64 libquadmath0:amd64 libradcli4 libreadline5:amd64 libreadline6:amd64 libreadline7:amd64 librelp0:amd64 librest-0.7-0:amd64 libroken18-heimdal:amd64 librsvg2-2:amd64 librsvg2-common:amd64 librtmp1:amd64 libsasl2-2:amd64 libsasl2-modules:amd64 libsasl2-modules-db:amd64 libsasl2-modules-gssapi-heimdal:amd64 libseccomp2:amd64 libsecret-1-0:amd64 libsecret-common libselinux1:amd64 libsemanage-common libsemanage1:amd64 libsensors4:amd64 libsepol1:amd64 libshine3:amd64 libsl0-heimdal:amd64 libslang2:amd64 libsm6:amd64 libsmartcols1:amd64 libsmbclient:amd64 libsnappy1v5:amd64 libsnmp-base libsnmp-session-perl libsnmp30:amd64 libsocket6-perl libsoup-gnome2.4-1:amd64 libsoup2.4-1:amd64 libsoxr0:amd64 libspeex1:amd64 libsqlite3-0:amd64 libss2:amd64 libssh2-1:amd64 libssl1.0.0:amd64 libssl1.0.2:amd64 libssl1.1:amd64 libstartup-notification0:amd64 libstdc++6:amd64 libstemmer0d:amd64 libswresample2:amd64 libsystemd0:amd64 libtalloc2:amd64 libtasn1-6:amd64 libtdb1:amd64 libtevent0:amd64 libtext-charwidth-perl libtext-iconv-perl libtext-wrapi18n-perl libthai-data libthai0:amd64 libtheora0:amd64 libtiff5:amd64 libtinfo5:amd64 libtirpc1:amd64 libtracker-sparql-1.0-0:amd64 libtre5:amd64 libtsan0:amd64 libtwolame0:amd64 libubsan0:amd64 libudev0:amd64 libudev1:amd64 libunbound2:amd64 libunistring0:amd64 libunivention-config0 libunivention-debug1 libunivention-license0 libunivention-policy0 libusb-0.1-4:amd64 libusb-1.0-0:amd64 libustr-1.0-1:amd64 libuuid1:amd64 libva-drm1:amd64 libva-x11-1:amd64 libva1:amd64 libvdpau1:amd64 libvorbis0a:amd64 libvorbisenc2:amd64 libvpx4:amd64 libwacom-common libwacom2:amd64 libwavpack1:amd64 libwayland-client0:amd64 libwayland-cursor0:amd64 libwayland-egl1-mesa:amd64 libwayland-server0:amd64 libwbclient0:amd64 libwebp6:amd64 libwebpdemux2:amd64 libwebpmux2:amd64 libwind0-heimdal:amd64 libwrap0:amd64 libx11-6:amd64 libx11-data libx11-xcb1:amd64 libx264-148:amd64 libx265-95:amd64 libxapian30:amd64 libxatracker2:amd64 libxau6:amd64 libxaw7:amd64 libxcb-dri2-0:amd64 libxcb-dri3-0:amd64 libxcb-glx0:amd64 libxcb-present0:amd64 libxcb-render0:amd64 libxcb-shape0:amd64 libxcb-shm0:amd64 libxcb-sync1:amd64 libxcb-util0:amd64 libxcb-xfixes0:amd64 libxcb1:amd64 libxcomposite1:amd64 libxcursor1:amd64 libxdamage1:amd64 libxdmcp6:amd64 libxext6:amd64 libxfixes3:amd64 libxfont1:amd64 libxfont2:amd64 libxft2:amd64 libxi6:amd64 libxinerama1:amd64 libxkbcommon0:amd64 libxkbfile1:amd64 libxml2:amd64 libxmlsec1 libxmlsec1-openssl libxmu6:amd64 libxmuu1:amd64 libxpm4:amd64 libxrandr2:amd64 libxrender1:amd64 libxshmfence1:amd64 libxslt1.1:amd64 libxt6:amd64 libxtables10 libxtables12:amd64 libxtst6:amd64 libxv1:amd64 libxvidcore4:amd64 libxxf86dga1:amd64 libxxf86vm1:amd64 libyaml-0-2:amd64 libzvbi-common libzvbi0:amd64 linux-base linux-compiler-gcc-6-x86 linux-headers-4.9.0-12-amd64 linux-headers-4.9.0-12-common linux-image-4.9.0-12-amd64 linux-image-4.9.0-12-amd64-signed linux-kbuild-4.9 linux-libc-dev:amd64 locales lockfile-progs login logrotate lsb-base lsb-release lsof lvm2 m17n-db make makepasswd manpages manpages-dev mawk memtest86+ mime-support mount multiarch-support mysql-common nano ncurses-base ncurses-bin ncurses-term net-tools netbase netcat-traditional ntp openbox openssh-client openssh-server openssh-sftp-server openssl openssl-blacklist os-prober pam-saml pass passwd patch pciutils perl perl-base perl-modules-5.24 pinentry-curses plymouth plymouth-themes poppler-data procps psmisc pwgen python python-alabaster python-apt python-apt-common python-babel python-babel-localedata python-cffi-backend python-chardet python-cherrypy3 python-click python-colorama python-cracklib python-crypto python-cryptography python-daemon python-dateutil python-debian python-decorator python-defusedxml python-dns python-dnspython python-docutils python-enum34 python-formencode python-idna python-imagesize python-imaging python-ipaddr python-ipaddress python-jinja2 python-lazy-object-proxy python-ldap python-ldb:amd64 python-lockfile python-lxml python-m2crypto python-magic python-mako python-markupsafe python-memcache python-minimal python-mysqldb python-netifaces python-notifier python-openssl python-pam python-paste python-pil:amd64 python-pkg-resources python-polib python-psutil python-pyasn1 python-pyasn1-modules python-pygments python-pysaml2 python-repoze.lru python-repoze.who python-requests python-roman python-routes python-ruamel.ordereddict python-ruamel.yaml python-samba python-setuptools python-six python-smbpasswd python-sphinx python-support python-talloc python-tdb python-tempita python-typing python-tz python-univention python-univention-admin-diary python-univention-appcenter python-univention-appcenter-docker python-univention-config-registry python-univention-debhelper python-univention-debug python-univention-directory-manager python-univention-directory-manager-cli python-univention-heimdal python-univention-ipcalc python-univention-lib python-univention-license python-univention-management-console python-univention-namespace python-univention-updater python-urllib3 python-webob python-zope.interface python2.7 python2.7-minimal python3 python3-cached-property python3-chardet python3-defusedxml python3-docker python3-dockerpty python3-dockerpycreds python3-docopt python3-jsonschema python3-minimal python3-notifier python3-pkg-resources python3-requests python3-six python3-texttable python3-urllib3 python3-websocket python3-yaml python3.5 python3.5-minimal rdate readline-common rsync rsyslog rsyslog-relp runc runit samba-common samba-common-bin samba-libs:amd64 screen sed sensible-utils sgml-base shared-mime-info shell-univention-lib smbclient sphinx-common ssl-cert sudo systemd systemd-sysv sysvinit sysvinit-utils tar tasksel tasksel-data tcpd tofrodos tree tzdata ucf udev univention-admin-diary-client univention-apache univention-apache-vhost univention-appcenter univention-appcenter-docker univention-archive-key univention-base-files univention-base-packages univention-bootsplash univention-config univention-directory-listener univention-directory-manager-tools univention-directory-policy univention-docker univention-errata-level univention-grub univention-heimdal-common univention-initrd univention-ipcalc univention-join univention-kernel-headers univention-kernel-image univention-management-console-frontend univention-management-console-login univention-management-console-module-lib univention-management-console-module-setup univention-management-console-module-sysinfo univention-management-console-server univention-management-console-web-server univention-network-common univention-runit univention-saml-schema univention-ssh univention-ssl univention-system-info univention-system-setup univention-system-setup-boot univention-updater univention-web-js univention-web-style usbutils util-linux vim vim-common vim-runtime vim-tiny vlan wamerican wget whiptail whois x11-common x11-utils x11-xkb-utils x11-xserver-utils xauth xfonts-base xfonts-encodings xfonts-utils xfsprogs xinit xkb-data xml-core xmlsec1 xserver-common xserver-xorg xserver-xorg-core xserver-xorg-input-libinput xserver-xorg-video-all xserver-xorg-video-amdgpu xserver-xorg-video-ati xserver-xorg-video-fbdev xserver-xorg-video-nouveau xserver-xorg-video-radeon xserver-xorg-video-vesa xserver-xorg-video-vmware xxd xz-utils zip zlib1g:amd64 zsync
Hope it helps, feel free to share.
Best regards
pate1337