Enable explicit FTP over SSL/TLS support (FTPES)

[asoluter]

Some servers like Synology may support only FTP/FTPES/SFTP, but not FTPS, so it was impossible to connect via FTPES using mobile device/Android TV. (FTPES is slightly faster than SFTP)

In desktop VLC you may enter the protocol manually, but in the mobile app it can only be picked from the preset list.

This PR just enables the existing VLC support for FTPES by adding it to the supported server protocol list.