Missing Input validation for filename in backups endpoint in Jellystat

Jellystat is a free and open source Statistics App for Jellyfin. In affected versions Jellystat is directly using a user input in the route(s). This can lead to Path Traversal Vulnerabilities. Since this functionality is only for admin(s), there is very little scope for abuse. However, the `DELETE` `files/:filename` can be used to delete any file. This issue has been addressed in version 1.1.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.