Protect access to scheduler queue with mutex

rerunbot.py

@@ -116,6 +116,7 @@ class ReplayBot(irc.bot.SingleServerIRCBot):
         if int(tags['user-id']) != self.control_user:
             send_response('Sorry @{0}, you are not allowed to do this'.format(tags['display-name']))
             return
+        with self.reactor.mutex:
             self.reactor.scheduler.queue.clear()
 
     def _post_message(self, user, msg):