Preserve rolling_update backward compatibility with ansible < 2.5
Preserve rolling_update backward compatibility with ansible < 2.5

Signed-off-by: Giulio Fidente <16c240e05639e6af23d6004da057b148e7020896@redhat.com>

ceph/ceph-ansible,fgal/ceph-ansible,fgal/ceph-ansible,ceph/ceph-ansible