Return the image key in get_image_ref in order to get the real content.
Return the image key in get_image_ref in order to get the real content.

PCManticore/argus-ci,stefan-caraiman/cloudbase-init-ci,AlexandruTudose/cloudbase-init-ci,micumatei/cloudbase-init-ci,cmin764/argus-ci,cloudbase/cloudbase-init-ci