event-logger: Update to version master-21

Update container-registry.zalando.net/teapot/event-logger to version master-21

Author: k8s-on-aws-manager-app[bot]

cluster/manifests/event-logger/statefulset.yaml

@@ -30,7 +30,7 @@ spec:
       serviceAccountName: kubernetes-event-logger
       containers:
       - name: logger
-        image: container-registry.zalando.net/teapot/event-logger:master-20
+        image: container-registry.zalando.net/teapot/event-logger:master-21
         args:
             - --snapshot-namespace=kube-system
             - --snapshot-name=kubernetes-event-logger