update NOTES.txt

Signed-off-by: unilinu <zhangchenglin_yewu@cmss.chinamobile.com>

Author: unilinu

charts/hub/templates/NOTES.txt

@@ -4,5 +4,5 @@ Your release is named {{ .Release.Name }}.
 
 Continue to install fleetboard-agent on clusters, and install fleetboard-agent in cluster by:
 
-  helm install fleetboard-agent fleetboard/fleetboard-agent --namespace fleetboard-system \
+  helm install fleetboard-agent fleetboard/fleetboard-agent \
   --set hub.hubURL=https://{{ .Values.tunnel.endpoint }}:6443 --set cluster.clusterID=cluster1