Univention Corporate Server 4.3 erratum 475 (bugfix)

This update addresses the following issues:
* The LDAP connections are reestablished in the UMC-Web-Server after
  a server password change. This causes that the correct portal entries
  for authenticated users are shown again.
* The pam_cracklib behavior prior to UCS 4.3 errata 450 has been restored.
  Therefore password changes do not require strong passwords anymore if no
  passord policy is defined in the domain.