Fix a race condition in test_create_delete_image()

The delete portion test_create_delete_image() in
ImagesOneServerTest has a race condition between the delete
and the assertRaises(). This commit fixes this by enabling
wait_for_resource_deletion() for the images_client and using that
after the delete request.

Fixes Bug 1187566

Change-Id: I13114d6c549756b3d753c9395f82d58cbaec04db
Merge "Fix a race condition in test_create_delete_image()"