Comment 5 for bug 1719730

Reviewed: https://review.openstack.org/509766
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=d288132dca7cc76dfc6679eda17bb8fcc62577de
Submitter: Jenkins
Branch: stable/pike

commit d288132dca7cc76dfc6679eda17bb8fcc62577de
Author: melanie witt <email address hidden>
Date: Wed Sep 27 17:27:56 2017 +0000

    Set group_members when converting to legacy request spec

    In Pike we converted the affinity filter code to use the RequestSpec
    object instead of legacy dicts. The filter used to populate server
    group info in the filter_properties and the conversion removed that.
    However, in the conductor, we are still converting RequestSpec back
    and forth between object and primitive, and there is a mismatch
    between the keys being set/get in filter_properties. So during a
    reschedule with a server group, we hit an exception
    "'NoneType' object is not iterable" in the RequestSpec.from_primitives
    method and the reschedule fails.

    This adds 'group_members' to the _to_legacy_group_info method to set
    the key.

    Closes-Bug: #1719730

    Change-Id: Icb418f2be575bb2ba82756fdeb67b24a28950746
    (cherry picked from commit 9d6632a67d91fb3c5145c14ac38011e919d6d8c0)