Arranging https connection among OS services

The patch arranges https connection among deployed OpenStack
services.

Change-Id: Ic25bf3a2c701686e85c0cbffef825a0f4957edcb
diff --git a/classes/cluster/os-ha-ovs/openstack/proxy.yml b/classes/cluster/os-ha-ovs/openstack/proxy.yml
index 8b2e13c..3f32322 100644
--- a/classes/cluster/os-ha-ovs/openstack/proxy.yml
+++ b/classes/cluster/os-ha-ovs/openstack/proxy.yml
@@ -14,4 +14,4 @@
       authority: ${_param:salt_minion_ca_authority}
       engine: salt
       mode: secure
-    salt_minion_ca_host: cfg01.${_param:cluster_domain}
+    salt_minion_ca_host: cfg01.${linux:system:domain}