re-fixed 0004602: Mismatch between Assign To dropdown and Assigned To whil updating
The original behaviour in bug_update*_page was correct and the dropdown was wrong because
it confused the status changes with any other changes.

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@3013 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9