Set mgmt interfaces to dhcp in contrail-labs

Closes-bug: #PROD-23882

Change-Id: I0d9faa34f92d4e771e28a7fe7e9ab1e33f3990ff
diff --git a/classes/cluster/os-ha-contrail-40/opencontrail/control.yml b/classes/cluster/os-ha-contrail-40/opencontrail/control.yml
index c8ac4f5..807043a 100644
--- a/classes/cluster/os-ha-contrail-40/opencontrail/control.yml
+++ b/classes/cluster/os-ha-contrail-40/opencontrail/control.yml
@@ -36,12 +36,14 @@
     network:
       interface:
         iface:
-          enabled: true
-          name: ${_param:opencontrail_control_interface_name}
-          type: eth
-          proto: static
-          address: ${_param:single_address}
-          netmask: 255.255.255.0
+          eth3: ${_param:linux_dhcp_interface}
+          eth4:
+            enabled: true
+            name: ${_param:opencontrail_control_interface_name}
+            type: eth
+            proto: static
+            address: ${_param:single_address}
+            netmask: 255.255.255.0
   keepalived:
     cluster:
       instance: