fix ns delete command

Change-Id: If0d154d4766cd64c41367aa868e1d20ac6f6e392
diff --git a/kubernetes/master/controller.sls b/kubernetes/master/controller.sls
index 3ecab62..d57434e 100644
--- a/kubernetes/master/controller.sls
+++ b/kubernetes/master/controller.sls
@@ -228,7 +228,7 @@
 
 kubernetes_namespace_delete_{{ name }}:
   cmd.run:
-    - name: kubectl get ns -o=custom-columns=NAME:.metadata.name | grep -v NAME | grep "{{ name }}" > /dev/null && kubectl delete ns "{{ name }}"
+    - name: kubectl get ns -o=custom-columns=NAME:.metadata.name | grep -v NAME | grep "{{ name }}" > /dev/null && kubectl delete ns "{{ name }} || true"
 
 {%- endif %}