Upgrading Univention 5.0-10 to 5.2-1

Extra info.

Following this: Remove LDAP schema extensions

root@external:~# cat objectclasses
univentionVirtualMachineGroupOC
univentionVirtualMachine
univentionVirtualMachineProfile
univentionVirtualMachineHostOC
univentionVirtualMachineCloudConnection
univentionVirtualMachineCloudType

root@external:~# cat attributes
univentionVirtualMachineGroup
univentionVirtualMachineUUID
univentionVirtualMachineOS
univentionVirtualMachineContact
univentionVirtualMachineDescription
univentionVirtualMachineProfileRef
univentionVirtualMachineProfileNamePrefix
univentionVirtualMachineProfileArch
univentionVirtualMachineProfileCPUs
univentionVirtualMachineProfileVirtTech
univentionVirtualMachineProfileRAM
univentionVirtualMachineProfileVNC
univentionVirtualMachineProfileInterface
univentionVirtualMachineProfileKBLayout
univentionVirtualMachineProfileKernel
univentionVirtualMachineProfileKernelParameter
univentionVirtualMachineProfileInitRAMfs
univentionVirtualMachineProfileBootDevices
univentionVirtualMachineAdvancedKernelConfig
univentionVirtualMachineProfileOS
univentionVirtualMachineProfilePVDisk
univentionVirtualMachineProfilePVInterface
univentionVirtualMachineProfileDiskspace
univentionVirtualMachineProfilePVCDROM
univentionVirtualMachineProfileRTCOffset
univentionVirtualMachineProfileDriverCache
univentionVirtualMachineProfileCPUModel
univentionVirtualMachineManageableBy
univentionVirtualMachineCloudConnectionTypeRef
univentionVirtualMachineCloudConnectionParameter
univentionVirtualMachineCloudConnectionImageSearchPattern
univentionVirtualMachineCloudConnectionIncludeUCSImages
univentionVirtualMachineCloudConnectionImageList

When I get to step 4.

univention-ldapsearch -LLLo ldif-wrap=no -f attributes ‘(%s=*)’ dn $(cat attributes)

univention-ldapsearch -LLLo ldif-wrap=no -f objectclasses ‘(objectClass=%s)’ dn

I only get BLANK lines no DN for the objects.

Not sure how to remove these not existing entries?