Remove unnecessary comment

synapse/handlers/user_directory.py

@@ -290,8 +290,6 @@ async def _handle_room_publicity_change(
             )
         else:
             raise Exception("Invalid event type")
-        # If change is None, no change. True => become world_readable/public,
-        # False => was world_readable/public
         if publicness is MatchChange.no_change:
             logger.debug("No change")
             return