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/etcd/defaults/main.yml

@@ -12,9 +12,9 @@ etcd_cert_group: root
 # Note: This does not set up DNS entries. It simply adds the following DNS
 # entries to the certificate
 etcd_cert_alt_names:
-  - "etcd.{{ system_namespace }}.svc.{{ dns_domain }}"
-  - "etcd.{{ system_namespace }}.svc"
-  - "etcd.{{ system_namespace }}"
+  - "etcd.kube-system.svc.{{ dns_domain }}"
+  - "etcd.kube-system.svc"
+  - "etcd.kube-system"
   - "etcd"
 
 etcd_script_dir: "{{ bin_dir }}/etcd-scripts"