Updated openstack/openstack
Project: openstack/keystone  d285b4cb9c2201090cf6687219a533eff192d0b7

Correct `nullable` values in models and migrations

* Region.description is declared as non-nullable in migration, so model nullable
value changed to False too.

* FederationProtocol.mapping_id must logically be not nullable. Provide a
migration script to add the NOT NULL constraint to the column.

Change-Id: I15a9e50b5461a112faca08f0ea68cbae2ce77d0d
Partial-Bug: #1292591