Add if enable_outward_rabbitmq in haproxy.cfg

Haproxy fails to deploy if outward group is not
in inventory.
This change adds an optional outward setting for
haproxy

Change-Id: I351578582b1057bb48ac69859583a5db13f0bfb8

ansible/roles/haproxy/templates/haproxy.cfg.j2

@@ -45,6 +45,7 @@ listen rabbitmq_management
   server {{ hostvars[host]['ansible_hostname'] }} {{ hostvars[host]['ansible_' + hostvars[host]['api_interface']]['ipv4']['address'] }}:{{ rabbitmq_management_port }} check inter 2000 rise 2 fall 5
 {% endfor %}
 
+{% if enable_outward_rabbitmq | bool %}
 listen outward_rabbitmq_management
   bind {{ kolla_internal_vip_address }}:{{ outward_rabbitmq_management_port }}
 {% for host in groups['outward-rabbitmq'] %}
@@ -63,6 +64,7 @@ listen outward_rabbitmq_external
 {% endfor %}
 {% endif %}
 {% endif %}
+{% endif %}
 
 {% if enable_mongodb | bool %}
 listen mongodb