Fixed typo in docs/topics/db/managers.txt.

docs/topics/db/managers.txt

@@ -214,7 +214,7 @@ appropriate for your circumstances, you can tell Django which class to use by
 setting :attr:`Meta.base_manager_name
 <django.db.models.Options.base_manager_name>`.
 
-Manager's aren't used when querying on related models. For example, if the
+Base managers aren't used when querying on related models. For example, if the
 ``Question`` model :ref:`from the tutorial <creating-models>` had a ``deleted``
 field and a base manager that filters out instances with ``deleted=True``, a
 queryset like ``Choice.objects.filter(question__name__startswith='What')``