Custom cursor retains reference after it has been deleted

If the user creates a custom cursor with a widget blueprint and then applies it via the project settings and then deletes the widget blueprint that is being reference. The setting will be set to none in the project settings, however it will still try to reference the deleted widget.

Example of error given:

Error The cursor class '/Game/NewWidgetBP.NewWidgetBP_C' was not found, check your custom cursor settings.

1. Open the Editor
2. Create a new widget blueprint
3. Open the project settings
4. Set the new widget blueprint as the default cursor under the User Interface settings
5. Play in Editor
6. Stop PIE
7. Delete the new widget blueprint
8. Play in editor again
9. Stop PIE
10. Notice the error that is given

Expected: The file path would be cleaned up when the blueprint in deleted
Result: The project settings still look for the deleted widget

Cosmetic bug: Configuration errors are not shown in the Project Settings