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/kubernetes/master/templates/manifests/kube-controller-manager.manifest.j2

@@ -2,7 +2,7 @@ apiVersion: v1
 kind: Pod
 metadata:
   name: kube-controller-manager
-  namespace: {{system_namespace}}
+  namespace: kube-system
   labels:
     k8s-app: kube-controller-manager
   annotations: