nfv virtual lab fixes

Change-Id: I657e75df6603bcf6b4a6725ea1d69efba522e44e
diff --git a/classes/cluster/virtual-mcp11-contrail-nfv/openstack/compute.yml b/classes/cluster/virtual-mcp11-contrail-nfv/openstack/compute.yml
index f09c9c6..9a7b4a4 100755
--- a/classes/cluster/virtual-mcp11-contrail-nfv/openstack/compute.yml
+++ b/classes/cluster/virtual-mcp11-contrail-nfv/openstack/compute.yml
@@ -46,6 +46,10 @@
           # - /usr/lib/contrail/if-vhost0
           # use_interfaces:
           # - ens4
+    system:
+      package:
+        liburcu4:
+          version: 0.9.1-3
   nova:
     compute:
       vncproxy_url: http://${_param:cluster_vip_address}:6080
@@ -70,3 +74,4 @@
     common:
       network:
         host: ${_param:openstack_control_address}
+