Scrollbar does not shrink when removing states in Designer

1. Open a QML file in Design mode.
2. Add a couple of states.
3. Switch to Edit mode.
   The vertical scrollbar has the right size to scroll to the file's bottom and back.
4. Switch to Design mode.
5. Remove a couple of states.
6. Switch to Edit mode.
   The vertical scrollbar still has the same size so now you can scroll far into an empty space.

The scrollbar should be updated whenever something changes the file's content.