Mobs will block false walls from closing

I observed a round where a player cheesed the AI Chamber during Malfunction by closing false walls on himself and using that as a shield against electrodes, lasers, and the cleaner fluid. This is to prevent that.

code/game/objects/structures/false_walls.dm

@@ -59,6 +59,10 @@
 		SetOpacity(0)
 		update_icon(0)
 	else
+		var/srcturf = get_turf(src)
+		for(var/mob/living/obstacle in srcturf) //Stop people from using this as a shield
+			opening = 0
+			return
 		do_the_flick()
 		density = 1
 		sleep(4)