re #4005 update function

git-svn-id: svn://develop.studip.de/studip/trunk@28571 c5b85792-5220-0410-ad23-ed5b6b8ad999
use Request::int() for time values in admin_seminare_assi.php, fixes #3875


git-svn-id: svn://develop.studip.de/studip/trunk@28572 c5b85792-5220-0410-ad23-ed5b6b8ad999