[1.6.x] Fixed #22859 -- Improved crossDomain technique in CSRF example.
[1.6.x] Fixed #22859 -- Improved crossDomain technique in CSRF example.

Thanks flisky for the report.

Backport of 0be4d64487 from master

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