This commit fixes an issue where opening zed using `--user-data-dir` with an empty directory would cause the first run to display a "Failed to migrate settings" error. This was caused by the migrator attempting to migrate an empty string, so if that's the case, we'll simply return `Ok(None)` and avoid attempting to migrate anything at all. Relates to #39400 Release Notes: - N/A Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>