Fixed #22747 -- Add backwards compatibility tip for new behavior of formset.save(commit=False).

        >>> for obj in formset.deleted_objects:

        ...     obj.delete()

    If you want to maintain backwards compatibility with Django 1.6 and earlier,

    you can do something like this::

        >>> try:

        >>>     # For Django 1.7+

        >>>     for obj in formset.deleted_objects:

        >>>         obj.delete()

        >>> except AssertionError:

        >>>     # Django 1.6 and earlier already deletes the objects, trying to

        >>>     # delete them a second time raises an AssertionError.

        >>>     pass

On the other hand, if you are using a plain ``FormSet``, it's up to you to

handle ``formset.deleted_forms``, perhaps in your formset's ``save()`` method,

as there's no general notion of what it means to delete a form.