Fixes delete first post (#735)

**Duplicate of Pullrequest 745**

This one does not contain any other commits. 


@JordanMussi chaning line 279 would redirect a moderator, after soft deleting a thread, but a moderator can see soft deleted threads, so I don't see the point in redirecting him... the issue also states that non moderators should be redirected... 

Just tested it again - it works fine for me...