Option 'AuthSyncModule::LDAP::GroupDN' is not working

[StefanRother-OTOBO]

In the OTOBO configuration for LDAP user synchronisation, the option $Self->{'AuthSyncModule::LDAP::GroupDN'} exists so that only certain groups are synchronised.
However, the check of the option is so far only implemented in $Self->{'AuthModule::LDAP::GroupDN'}, as it is normally not needed during synchronisation.

However, there is a special case when Kerberos SSO is configured, the web server takes over the authentication and we can only restrict the general access to the OTOBO agent interface by not creating the user in OTOBO if he is not included in the group.