Deleted image should not show as a link on instance details panel

[Ying Zuo]

Steps to reproduce:
1. Create an instance
2. Delete the image used for the instance
3. Go to instance details panel

Note that the Image Name field is a dash with a link. The user will get an error when clicking on the link.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/439859

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/439859
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=a35cf2da28d2732acebc297f44a222f2cd7028da
Submitter: Jenkins
Branch: master

commit a35cf2da28d2732acebc297f44a222f2cd7028da
Author: Ying Zuo <email address hidden>
Date: Wed Mar 1 13:21:41 2017 -0800

    Only show image name as a link when the image exists

    Updated the nova api to return None when the image name
    is not available, for example, when it's deleted.

    Added a check for the image name before showing it as
    a link.

    Change-Id: I342b23dfd8352182f50c41054d2dbb3eae854839
    Closes-bug:1668783

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/horizon 12.0.0.0b2 development milestone.