revert the previous gpc_api and bug_update.php and apply a better fix
fix for 0005587: Custom field date type reset to blank
fix for 0005651: The values in a mulitselect custom field disappear
when updating the status of the issue

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@3567 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9