better wall init and clearing

mapsloader.lua

@@ -1,12 +1,10 @@
 function LoadMap(lvl)
-	ClearWalls()
-
 	local mapfilelocation = "maps/"
 	local extention = ".lua"
 	local mapname = mapfilelocation .. "map" .. lvl .. extention
 
 	GameMap = STI(mapname)
-	--Walls = {}
+	Walls = {}
 	if GameMap.layers["Walls"] then
 		for _, obj in ipairs(GameMap.layers["Walls"].objects) do
 			local wall = World:newRectangleCollider(obj.x, obj.y, obj.width, obj.height)