The cold to reactivate an activity could sometimes switch to 'Anonymous User' and not switch back.

Move the user switching logic to inside the 'try' block that restores the user afterwards.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@30778 20353a03-c40f-0410-a6d1-a30d3c3de9de