Avoid using namespace that is a reserved object

Author: sdwerwed

content/en/docs/tasks/run-application/run-replicated-stateful-application.md

@@ -39,6 +39,7 @@ on general patterns for running stateful applications in Kubernetes.
   [ConfigMaps](/docs/tasks/configure-pod-container/configure-pod-configmap/).
 * Some familiarity with MySQL helps, but this tutorial aims to present
   general patterns that should be useful for other systems.
+* You are using the default namespace or another namespace that does not contain any conflicting objects.
 
 
 
@@ -540,4 +541,3 @@ kubectl delete pvc data-mysql-4
 
 
 
-