add ignoreDifferences to app.istiod

Author: Krzysztof Romanowski

example/helm/app.istiod.yaml

@@ -22,6 +22,11 @@ spec:
     - repoURL: https://github.com/kromanow94/kubeflow-manifests.git
       targetRevision: kubeflow-0.5.0-rc.2
       ref: values
+  ignoreDifferences:
+    - group: admissionregistration.k8s.io
+      jqPathExpressions:
+        - .webhooks[] | .failurePolicy
+      kind: ValidatingWebhookConfiguration
   syncPolicy:
     automated:
       prune: true