[1.6.x] Fixed #21294 -- Clarified the logout next_page argument.
[1.6.x] Fixed #21294 -- Clarified the logout next_page argument.

Thanks wim at go2people.nl for the report.

Backport of 51e6575472 from master

redhat-openstack/django,dex4er/django,felixjimenez/django,django-nonrel/django,felixjimenez/django,felixjimenez/django,dex4er/django,django-nonrel/django,django-nonrel/django,redhat-openstack/django,redhat-openstack/django,dex4er/django,django-nonrel/django,felixjimenez/django,redhat-openstack/django