Wait one move to put a wall

Avoid to put a wall on the player itself.

Player.gd

@@ -57,6 +57,8 @@ func _physics_process(delta):
 	if is_moving:
 		return
 
+	grid.set_cell(posix - dirx, posiy - diry, 1)
+
 	dire += dire_delta
 
 	if dire_delta == -1:
@@ -72,8 +74,6 @@ func _physics_process(delta):
 	turn(dire)
 	dire_delta = 0
 
-	grid.set_cell( posix, posiy, 1)
-
 	posix += dirx
 	posiy += diry