url encoded file names

gsutil -m rsync -d -r s3://some-stuff-ceph gs://some-stuff-gcp

```
Caught non-retryable exception while listing s3://some-stuff-ceph/: NotFoundException: 404 Attempt to get key for
"s3://some-stuff-ceph/image/15/01/22/54c109b42174e/_orig/unnamed #.png" failed. This can happen
if the URI refers to a non-existent object or if you meant to operate on a
directory (e.g., leaving off -R option on gsutil cp, mv, or ls of a bucket)
CommandException: Caught non-retryable exception - aborting rsync
```
i know, name of the file is bad, but why it can not be transcoded into 'unnamed%20%23.png'?