[CORD-1505]
Support multiple external interface names on compute nodes managed by VTN

Change-Id: I01f21a778bba60f8f040d714e4b3ec776557af19
diff --git a/profile_manifests/opencloud.yml b/profile_manifests/opencloud.yml
index dd549ee..95ddd93 100644
--- a/profile_manifests/opencloud.yml
+++ b/profile_manifests/opencloud.yml
@@ -133,8 +133,9 @@
 management_network_ip: 172.27.0.1/24
 data_plane_ip: 10.168.0.253/24
 
-# External interface name on compute nodes
-compute_external_interface: eth0
+# External interface names on compute nodes
+compute_external_interfaces:
+  - eth0
 
 # ONOS version
 onos_docker_image: "onosproject/onos:1.8.7"