Define correct cluster_public_host on proxy node for Pike models

We have only one proxy node and do not have keepalived enabled on it
however redirect is configured incorrectly for horizon and points to
controller node VIP. This patch fixes redirect.

Change-Id: I2c1b4701b245bb3e2aad9c36b292dc4cd4fb28c6
Related-Prod: PROD-19561
diff --git a/classes/cluster/virtual-mcp-pike-dvr/openstack/proxy.yml b/classes/cluster/virtual-mcp-pike-dvr/openstack/proxy.yml
index 3420f43..d6ea854 100644
--- a/classes/cluster/virtual-mcp-pike-dvr/openstack/proxy.yml
+++ b/classes/cluster/virtual-mcp-pike-dvr/openstack/proxy.yml
@@ -7,9 +7,10 @@
 - cluster.virtual-mcp-pike-dvr
 parameters:
   _param:
+    cluster_public_host:  ${_param:openstack_proxy_address}
     nginx_proxy_ssl:
       enabled: true
       authority: ${_param:salt_minion_ca_authority}
       engine: salt
       mode: secure
-    salt_minion_ca_host: cfg01.${_param:cluster_domain}
\ No newline at end of file
+    salt_minion_ca_host: cfg01.${_param:cluster_domain}