Stop templating kube-system namespace and creating it (#2545)

Kubernetes makes this namespace automatically, so there is
no need for kubespray to manage it.

roles/network_plugin/contiv/templates/contiv-config.yml.j2

@@ -5,7 +5,7 @@ kind: ConfigMap
 apiVersion: v1
 metadata:
   name: contiv-config
-  namespace: {{ system_namespace }}
+  namespace: kube-system
 data:
   # The location of your cluster store. This is set to the
   # avdertise-client value below from the contiv-etcd service.