Updated openstack/openstack
Project: openstack/nova  cbfa5cb2c570671c992509adcbbae09d78f07645

libvirt: remove unused list_instance_ids method

All code has been converted to use list_instance_domains so the
list_instance_ids method can finally be removed.

Blueprint: libvirt-domain-listing-speedup
Change-Id: I9ce33cda5608796e0eec4ec0804ee179a4704d9d