fix ingess nginx install in aks example

Author: anson627

examples/azure/aks-new_cluster/README.md

@@ -48,14 +48,14 @@ az aks get-credentials --resource-group <azure_resource_group_name> --name <aks_
 #### Install the Nginx ingress controller
 
 ```shell
-helm repo add nginx https://kubernetes.github.io/ingress-nginx
 helm upgrade ingress-nginx nginx/ingress-nginx \
   --version 4.12.1 \
   --namespace ingress-nginx \
   --create-namespace \
   --set controller.service.type=LoadBalancer \
   --set controller.service.annotations."service\.beta\.kubernetes\.io/azure-load-balancer-health-probe-request-path"=/healthz \
   --set controller.allowSnippetAnnotations=true \
+  --set controller.progressDeadlineSeconds=600 \
   --install
 ```