Univention Corporate Server 4.1 erratum 407 (bugfix)

This update addresses the following issue(s):
* A warning message is shown when the currently used UCS version
  is out of maintenance.
* Added required dependencies explicitly to the package.
* When upgrading Apps via univention-upgrade and this upgrade fails, do not
  abort univention-upgrade.
* When upgrading Apps via univention-upgrade, in some situations a wrong App
  version was shown as the one to upgrade to. This was only a display issue,
  though. The upgrade was run with the correct App version.
* The updater cleans the package cache now after a successful update.