Destroy gameScreen after all other graphics are destroyed

This is because destroying the renderer causes use-after-frees since the
renderer destroys all textures when it gets destroyed.

This fixes a Valgrind error where an invalid read occurs because the
font textures get destroyed again after the renderer is destroyed.

desktop_version/src/main.cpp

@@ -823,9 +823,9 @@ static void cleanup(void)
 
     graphics.grphx.destroy();
     graphics.destroy_buffers();
-    gameScreen.destroy();
     graphics.destroy();
     font::destroy();
+    gameScreen.destroy();
     music.destroy();
     map.destroy();
     NETWORK_shutdown();