[1.7.x] Fixed typo in docs/topics/db/managers.txt

.. classmethod:: from_queryset(queryset_class)

For advance usage you might want both a custom ``Manager`` and a custom

For advanced usage you might want both a custom ``Manager`` and a custom

``QuerySet``. You can do that by calling ``Manager.from_queryset()`` which

returns a *subclass* of your base ``Manager`` with a copy of the custom

``QuerySet`` methods::