fix missing nf_conntrack_tcp_timeout_time_wait netfilter for opencontrail

Change-Id: I4f3dcc676390c63ccea2101b6c974569d76c5e1d
diff --git a/opencontrail/control/control.yml b/opencontrail/control/control.yml
index 9c1d905..fdc4f7d 100644
--- a/opencontrail/control/control.yml
+++ b/opencontrail/control/control.yml
@@ -38,3 +38,8 @@
         port: 9042
       network:
         host: ${_param:cluster_vip_address}
+  linux:
+    system:
+      kernel:
+        modules:
+        - nf_conntrack_ipv4