[1.6.x] Fixed typo in docs/ref/django-admin.txt
[1.6.x] Fixed typo in docs/ref/django-admin.txt

Thanks Wes Kendall for the report.

Backport of ce3d9f847d from master

felixjimenez/django,felixjimenez/django,felixjimenez/django,django-nonrel/django,django-nonrel/django,redhat-openstack/django,redhat-openstack/django,redhat-openstack/django,django-nonrel/django,felixjimenez/django,django-nonrel/django,redhat-openstack/django