openstack: Do not use layer2 mode for Octavia LB

If you specify the subnet of a member, Octavia will Load Balance the
connections to that member in L2 mode, i.e., it will create a port for
the Amphora in the destination subnet so that the communication
Amphora->Member happens without routing. While this provides good
networking characteristics, it is currently buggy in CentOS/RHEL.

Change-Id: I45d08ea724b49c6de0504cf76a29131f133752ba
Signed-off-by: Antoni Segura Puimedon <antonisp@celebdor.com>

roles/openshift_openstack/templates/heat_stack_server.yaml.j2

@@ -339,7 +339,9 @@ resources:
       pool: { get_param: api_lb_pool }
       protocol_port: {{ openshift_master_api_port }}
       address: { get_attr: [server, first_address]}
+{% if openshift_openstack_lbaasv2_provider != "Octavia"  %}
       subnet: { get_param: subnet }
+{% endif %}
 
   router_lb_pool_member_http:
     condition: