Re-initialise when restarting 1-node cluster
Re-initialise when restarting 1-node cluster

Modify the mysql restart handler so that the arg '--wsrep-new-cluster'
is supplied when restarting a cluster of one node.

This fixes an issue where restarting a single-node cluster fails because
there are no other members of the cluster available with which to
re-establish a connection.

Change-Id: I2cdc1e61dde68e441c6927f85123467568df5e27

openstack/openstack-ansible-galera_server,openstack/openstack-ansible-galera_server,os-cloud/openstack-ansible-galera_server,os-cloud/openstack-ansible-galera_server