Univention update error from 4.4.2 to 4.4.6

I am trying to update from version 4.4.2 to version 4.4.6. After a short while the system returns with an error.

27.10.20 07:27:36.451 DEBUG_INIT
**** Starting univention-updater with parameter=[’/usr/share/univention-updater/univention-updater’, ‘net’, ‘–updateto’, ‘4.4-6’, ‘–ignoressh’, ‘–ignoreterm’]
starting net mode
—>DBG:update_available(mode=net, cdrom_mount_point=/media/cdrom, iso=None)
Checking network repository
Update to = 4.4-5
**** Downloading scripts at Tue Oct 27 07:27:38 2020
Error: Update aborted due to verification error:
Verification error: Invalid signature: gpgv: keyblock resource ‘/etc/apt/trusted.gpg’: Bestand of map bestaat niet
gpgv: Signature made di 14 jul 2020 11:22:59 CEST
gpgv: using RSA key 36602BA86B8BFD3C
gpgv: Good signature from “Univention Corporate Server 4.x packages@univention.de

This can and should only be disabled temporarily using the UCR
variable ‘repository/online/verify’.

The problem is that I don’t know how to disable the variable mentioned above.

I finally got it working:
ucr set repository/online/verify=false