Don't do last visit stuff on POSTs.

It isn't really necessary to do it on every POST_vote, POST_hide etc.

r2/r2/controllers/reddit_base.py

@@ -721,6 +721,7 @@ class MinimalController(BaseController):
 
         # update last_visit
         if (c.user_is_loggedin and not g.disallow_db_writes and
+            request.method.upper() != "POST" and
             request.path != '/validuser'):
             c.user.update_last_visit(c.start_time)