* Polished the malf timer logic

* added a protection to prevent division by 0 when all hacked apcs are destroyed
* added a midnight rollover check for the MC (fixes #4905)
* toggling breakers won't add/remove a hacked APC from the AI apcs pool anymore

code/controllers/master_controller.dm

@@ -118,6 +118,10 @@ var/global/pipe_processing_killed = 0
 			if(!Failsafe)	new /datum/controller/failsafe()
 
 			var/currenttime = world.timeofday
+
+			if((last_tick_timeofday - currenttime) > 1e5) //midnight rollover protection
+				last_tick_timeofday -= MIDNIGHT_ROLLOVER
+
 			last_tick_duration = (currenttime - last_tick_timeofday) / 10
 			last_tick_timeofday = currenttime