use get to check stdout_lines
use get to check stdout_lines

During the initial play, the docker command doesn't not exist and then
there is no stdout_lines to the command. So get allows us to fix this by
declaring an array if the command fails.

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

font/ceph-ansible,jtaleric/ceph-ansible,travmi/ceph-ansible,font/ceph-ansible,travmi/ceph-ansible,fgal/ceph-ansible,jtaleric/ceph-ansible,ceph/ceph-ansible,ceph/ceph-ansible,fgal/ceph-ansible