fix metadata for contrail 4.x

Change-Id: I5a5aa39f72cd745cf12309fe8e9e65d7b4075f5e
diff --git a/opencontrail/control/single4_0.yml b/opencontrail/control/single4_0.yml
index de6f558..ded5289 100644
--- a/opencontrail/control/single4_0.yml
+++ b/opencontrail/control/single4_0.yml
@@ -128,6 +128,8 @@
         - host: ${_param:single_address}
     collector:
       config_only: true
+      identity:
+        host: ${_param:openstack_control_address}
       discovery:
         host: None
       database: