When the opts are being pass through the go side, we get back empty string values instead of nil values, so the `||=` assignment was not working to populate the default owner and group. This was causing the rsync_post hook to fail on linux guests.
When the opts are being pass through the go side, we get back empty string values instead of nil values, so the `||=` assignment was not working to populate the default owner and group. This was causing the rsync_post hook to fail on linux guests.