Univention Corporate Server 4.4 erratum 348 (bugfix)

This update addresses the following issues:
* The package now uses dh_python2 instead of python-support.
  Therefore python modules are installed into
  /usr/lib/python2.7/dist-packages/univention/admin/
* A link to a support article for printer driver distribution is now
  shown in the UMC printers module.
* A TypeError is prevented during logging of invalid date values
  in the UDM REST service.