[1.6.x] Fixed #22454 - Changed compatibility warning hint for test runner.
[1.6.x] Fixed #22454 - Changed compatibility warning hint for test runner.

Backport of 214d1e1b0f from master

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