[1.6.x] Fixed #22419 -- Typo in docs/topics/db/multi-db.txt.
[1.6.x] Fixed #22419 -- Typo in docs/topics/db/multi-db.txt.

Thanks Josh Kupershmidt.

Backport of c487b1e230 from master

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