Don't delete rbd ephemeral disks when revert-resize instances.
Don't delete rbd ephemeral disks when revert-resize instances.

if images_type is rbd, don't destroy it when revert-resize.

Signed-off-by: apporc <eace494683e27f0eb70140bd4063efbda0256f8e@gmail.com>

eayunstack/nova,eayunstack/nova