changed k8s.gcr.io to registry.k8s.io (#8667)

docs/examples/customization/custom-errors/custom-default-backend.helm.values.yaml

@@ -3,7 +3,7 @@ controller:
 defaultBackend:
   enabled: true
   image:
-    registry: k8s.gcr.io
+    registry: registry.k8s.io
     image: ingress-nginx/nginx-errors
     tag: "0.48.1"
   extraVolumes:

docs/examples/customization/custom-errors/custom-default-backend.yaml

@@ -36,7 +36,7 @@ spec:
     spec:
       containers:
       - name: nginx-error-server
-        image: k8s.gcr.io/ingress-nginx/nginx-errors:0.49.0
+        image: registry.k8s.io/ingress-nginx/nginx-errors:0.49.0
         ports:
         - containerPort: 8080
         # Setting the environment variable DEBUG we can see the headers sent