Updated openstack/openstack
Project: openstack/heat  2467649f6d8b2dbc575b33021313b32f493e5483

Allow VolumeAttachments to delete in parallel

Deleting a VolumeAttachment was still blocking; this change allows other
resources to be processed while we are waiting for the volume to be
detached.

Change-Id: Id1a7bf2a353cb1f255ab335ab8c39edbeb4dc292