Univention Corporate Server 4.1 erratum 194 (bugfix)

This update addresses the following issue(s):
* When Docker Apps were updated, a new version of the shipped join script was
  not recognized. This has been fixed, the join script is now correctly
  installed and executed.
* The button on the App page which read "Open module" or "Open Website" has
  been relabeled to just "Open".
* One could not uninstall Apps that other Apps required to be installed
  somewhere in the domain, even if this App was installed several times. This
  has been fixed.