[1.1.X] Fixed doc markup error that resulted in no anchor tag for the model admin queryset method.

This uses the ``HttpRequest`` instance to filter the ``Car`` foreign key field

to only the cars owned by the ``User`` instance.

.. method:: ModelAdmin.queryset(self, request):

.. method:: ModelAdmin.queryset(self, request)

The ``queryset`` method on a ``ModelAdmin`` returns a

:class:`~django.db.models.QuerySet` of all model instances that can be