Updated openstack/openstack
Project: openstack/nova  e239791fc7f79d53d76ea12591e1fb43691ec4e9

Add helper methods to convert disk

Add a _disk_raw_to_qcow2 and _disk_qcow2_raw methods which
convert disk.
Update finish_migration to use these helpers.

Change-Id: If98f7fc04668916fda788afb65116a89463b0020
Related-Bug: #1298975