refs #3565 : bugfixing thread-view

git-svn-id: svn://develop.studip.de/studip/trunk@26906 c5b85792-5220-0410-ad23-ed5b6b8ad999
refs #3565 : bugfixing thread-view

git-svn-id: svn://develop.studip.de/studip/trunk@26907 c5b85792-5220-0410-ad23-ed5b6b8ad999