Removed tu-darmstadt-ros-pkg source entries

During [RoboCup 2014](http://www.robocup2014.org) there might be several commits in these repos that cause failing devel jobs and will be cleaned up afterwards. Therefore we better switch it off until after the event to avoid build server load and email notifications.
Merge pull request #5057 from meyerj/patch-5

Removed tu-darmstadt-ros-pkg source entries