Fixed typo -- "a" user, not "an" user

The only thing this does is create those extra permissions when you run

:djadmin:`manage.py migrate <migrate>`. Your code is in charge of checking the

value of these permissions when an user is trying to access the functionality

value of these permissions when a user is trying to access the functionality

provided by the application (viewing tasks, changing the status of tasks,

closing tasks.) Continuing the above example, the following checks if a user may

view tasks::

.. module:: django.contrib.auth

   :synopsis: Django's authentication framework.

Django comes with an user authentication system. It handles user accounts,

Django comes with a user authentication system. It handles user accounts,

groups, permissions and cookie-based user sessions. This section of the

documentation explains how the default implementation works out of the box, as

well as how to :doc:`extend and customize </topics/auth/customizing>` it to