Remove DockerCephDaemonImage from tht/overcloud-ceph-ansible.yaml
Remove DockerCephDaemonImage from tht/overcloud-ceph-ansible.yaml

This setting will instead be created by init.sh which it genereates
the docker_registry.yaml which should now be defaulting to
docker.io/ceph/daemon:tag-stable-3.0-luminous-centos-7

fultonj/tripleo-ceph-ansible,fultonj/tripleo-ceph-ansible