GUI2/Window: draw background image first instead of last

Originally was going to do this as workaround for the background tiling over the borders,
but I fixed the root cause of that instead. Still, this just makes more sense.

data/gui/widget/window_default.cfg

@@ -22,6 +22,15 @@
 
 				{PRE_COMMIT}
 
+				[image]
+					x = 2
+					y = 2
+					w = "(width - 4)"
+					h = "(height - 4)"
+					name = "dialogs/{BASE_NAME}-background.png"
+					resize_mode = "tile"
+				[/image]
+
 				[rectangle]
 					x = 0
 					y = 0
@@ -42,15 +51,6 @@
 					border_color = {GUI__BORDER_COLOR_DARK}
 				[/rectangle]
 
-				[image]
-					x = 2
-					y = 2
-					w = "(width - 4)"
-					h = "(height - 4)"
-					name = "dialogs/{BASE_NAME}-background.png"
-					resize_mode = "tile"
-				[/image]
-
 			[/draw]
 
 		[/background]