Set mgmt interfaces to dhcp in contrail-labs

Closes-bug: #PROD-23882

Change-Id: I0d9faa34f92d4e771e28a7fe7e9ab1e33f3990ff
diff --git a/classes/cluster/os-ha-contrail-40/openstack/control.yml b/classes/cluster/os-ha-contrail-40/openstack/control.yml
index 424e2bf..0234048 100644
--- a/classes/cluster/os-ha-contrail-40/openstack/control.yml
+++ b/classes/cluster/os-ha-contrail-40/openstack/control.yml
@@ -49,6 +49,7 @@
           version: latest
     network:
       interface:
+        ens3: ${_param:linux_dhcp_interface}
         ens4:
           enabled: true
           type: eth