v6.3.8

1. [General] Remove unused dependencies
2. [Packaging] Show a loading Dashboard while the local backend is not ready
3. [FM] Change download method to mitigate a HTTPS download issue in Chromium
4. [SFTP] Try to recover from broken symlinks when downloading
5. [SFTP] Support deleting a long list of files
6. [QuotaUsage] Fix quota usage percentage display issue
7. [Packaging] add 'progress_page' as protocol interception keyword