fix missing nf_conntrack_tcp_timeout_time_wait netfilter for opencontrail

Change-Id: I4f3dcc676390c63ccea2101b6c974569d76c5e1d
diff --git a/opencontrail/control/single.yml b/opencontrail/control/single.yml
index efdc267..064418e 100644
--- a/opencontrail/control/single.yml
+++ b/opencontrail/control/single.yml
@@ -12,6 +12,9 @@
           version: 1.0.1-0contrail1
         contrail-api-cli:
           version: latest
+      kernel:
+        modules:
+        - nf_conntrack_ipv4
   haproxy:
     proxy:
       listen: