fix OpenContrail 4.0 metadata

Change-Id: I527a5a9cf93af3feec6fdd86a0ef8ba6c296bf9a
diff --git a/opencontrail/control/single4_0.yml b/opencontrail/control/single4_0.yml
index cbd6520..365ed20 100644
--- a/opencontrail/control/single4_0.yml
+++ b/opencontrail/control/single4_0.yml
@@ -84,6 +84,8 @@
         address: ${_param:single_address}
       discovery:
         host: None
+      api:
+        host: ${_param:single_address}
       analytics:
         members:
         - host: ${_param:single_address}