Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

cluster/update-storage-objects.sh: Fix to ignore deleted objects

**What this PR does / why we need it**:
This PR fixes to ignore deleted objects in `cluster/update-storage-objects.sh`.  If it failed to fetch the object at [here](https://github.com/kubernetes/kubernetes/blob/master/cluster/update-storage-objects.sh#L101), it must ignore the object, but currently this script exits as follows after 5 tries:

```
$ ./cluster/update-storage-objects.sh
Error from server (NotFound): events "minikube.151d894772669d981" not found
Looks like minikube.151d894772669d98 got deleted. Ignoring it
Error from server (NotFound): events "minikube.151d894772669d981" not found
Looks like minikube.151d894772669d98 got deleted. Ignoring it
Error from server (NotFound): events "minikube.151d894772669d981" not found
Looks like minikube.151d894772669d98 got deleted. Ignoring it
Error from server (NotFound): events "minikube.151d894772669d981" not found
Looks like minikube.151d894772669d98 got deleted. Ignoring it
Error from server (NotFound): events "minikube.151d894772669d981" not found
Looks like minikube.151d894772669d98 got deleted. Ignoring it
Error: failed to update events/minikube.151d894772669d98 in default namespace after 5 tries
```

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```