Cells ImagePropertiesFilter can raise exceptions

[Christopher Lefelhocz]

In a misconfigured scenario the ImagePropertiesFilter can raise an exception which causes the image to be unbuildable in the region. This happens when the capabilities is set for prominent_hypervisor_version to '[]' or an empty list. We should be resilient to this case and handle the exception.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/107808

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/107808
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=70e0d3f13bd2ffaa19ddb6a50074723a7dbb0226
Submitter: Jenkins
Branch: master

commit 70e0d3f13bd2ffaa19ddb6a50074723a7dbb0226
Author: Christopher Lefelhocz <email address hidden>
Date: Thu Jul 17 14:17:47 2014 -0500

    Fix Cells ImagePropertiesFilter can raise exceptions

    In a misconfigured scenario the ImagePropertiesFilter can raise an
    exception which causes the image to be unbuildable in the region. This
    happens when the capabilities is set for prominent_hypervisor_version
    to an empty list.

    Change-Id: I17bd9d87fa69ad34b19591018543a34dfd050978
    Closes-Bug: 1343462