prevent lost update of activation key on email change, re #2962

git-svn-id: svn://develop.studip.de/studip/trunk@26132 c5b85792-5220-0410-ad23-ed5b6b8ad999
fix extraction of parameters from request, re #1922, fixes #3422

git-svn-id: svn://develop.studip.de/studip/trunk@26133 c5b85792-5220-0410-ad23-ed5b6b8ad999