don't enable contrail_network_manager by default

Change-Id: I92956563cf022a4600749eaf886d6273bdf6b130
diff --git a/metadata/service/master/single.yml b/metadata/service/master/single.yml
index 14d9656..524737e 100644
--- a/metadata/service/master/single.yml
+++ b/metadata/service/master/single.yml
@@ -54,7 +54,7 @@
           image: calico/kube-policy-controller:v0.5.4
           namespace: kube-system
         contrail_network_controller:
-          enabled: true
+          enabled: False
           namespace: kube-system
           image: yashulyak/contrail-controller:latest
         virtlet: