Cleaned up UserAdmin.get_form() that worked around a bug fixed in 23e1b59c.

        """

        defaults = {}

        if obj is None:

            defaults.update({

                'form': self.add_form,

                'fields': admin.util.flatten_fieldsets(self.add_fieldsets),

            })

            defaults['form'] = self.add_form

        defaults.update(kwargs)

        return super(UserAdmin, self).get_form(request, obj, **defaults)