docker_exec: add a message for dying container
docker_exec: add a message for dying container

If the container is about to exit with a rc different than 0 we can tell
the user how to maintain it alive next time they run it.

Signed-off-by: Sébastien Han <62d754cc350e84d3b1c32ae79f976f5348e74a40@redhat.com>

ceph/ceph-docker,ceph/ceph-docker