Comment 8 for bug 1704788

Reviewed: https://review.openstack.org/490110
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=3eefcce2553856a1635a62fecf73cd9a2d9097cb
Submitter: Jenkins
Branch: stable/ocata

commit 3eefcce2553856a1635a62fecf73cd9a2d9097cb
Author: Sylvain Bauza <email address hidden>
Date: Tue Jul 18 16:33:49 2017 +0200

    Accept any scheduler driver entrypoint

    We broke the possibility in Ocata with Icdcf839b6d28893694bfa1355e9dbe8dbb5ea8c3
    to use other scheduler drivers but the ones we provided in tree.

    Unfortunately, that was an incidental change without any communication.

    Removing the choices kwarg will allow operators to run their own scheduler driver.
    Whether Nova would stop supporting custom drivers would require a totally separate
    change which would clearly communicate thru a deprecation notice but that is not
    the intent for that bugfix, which aims only to bring back the capability.

    Change-Id: I346881bc3bc48794b139cc471be1de11c49b8ee3
    Closes-Bug: #1704788
    (cherry picked from commit 1e5c7b52a403e708dba5a069dd86b628a4cb952c)