Revert "Slightly increase brick hitbox"

Fix bug where some damage were missed.

This reverts commit 2f458e227d59ec6e6192d4d5700f747e3f9357b7.

godot/scenes/main.tscn

@@ -25,7 +25,7 @@ extents = Vector2( 300, 50 )
 extents = Vector2( 200, 50 )
 
 [sub_resource type="RectangleShape2D" id=5]
-extents = Vector2( 20.5, 10.5 )
+extents = Vector2( 20, 10 )
 
 [sub_resource type="TileSet" id=6]
 0/name = "brik.png 0"