qa/workunits/rbd: wait for image deleted before checking health

When a primiry image is being deleted, the mirrored image might
temporary be reported in error state, before deletion is propagated.

Signed-off-by: Mykola Golub <mgolub@mirantis.com>
(cherry picked from commit 8dbe42d)

qa/workunits/rbd/rbd_mirror_stress.sh

@@ -158,6 +158,7 @@ do
 done
 
 testlog "TEST: image deletions should propagate"
+wait_for_pool_images ${CLUSTER2} ${POOL} 0
 wait_for_pool_healthy ${CLUSTER1} ${POOL} 0
 for i in `seq 1 ${IMAGE_COUNT}`
 do