Always template a localhost config when server

If the galera_client role is templating its config file on a galera
server host it should always use a localhost address.

Change-Id: I468b171c1e72697ea6450fe08aa0acb3faf91201

templates/client.my.cnf.j2

@@ -1,6 +1,10 @@
 # {{ ansible_managed }}
 
 [client]
-host={{ galera_address }}
+host={% if inventory_hostname in galera_cluster_members %}
+127.0.0.1
+{% else %}
+{{ galera_address }}
+{% endif %}
 user={{ galera_root_user }}
 password={{ galera_root_password }}

tests/inventory

@@ -1,2 +1,4 @@
 [all]
 localhost
+
+[galera_all]