Too remove potential excessive garbage collection per tick. We will be reusing lists for overlays instead of deleting and creating them.

the .Cut() proc on a list will empty a list by default. This also will set the len to 0.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@5465 316c924e-a436-60f5-8080-3fe189b3f50e

code/modules/projectiles/projectile/change.dm

@@ -16,7 +16,7 @@
 		M.monkeyizing = 1
 		M.canmove = 0
 		M.icon = null
-		M.overlays = null
+		M.overlays.Cut()
 		M.invisibility = 101
 
 		if(istype(M, /mob/living/silicon/robot))