Language-specific URLs

[TMueller83]

Hi, thank you for creating TTS-Backup! Since v13.0 of Tabletop Simulator it is possible to assign language-specific URLs to the assets. Example: {en}url1{fr}url2, and so on. Currently, TTS-Backup seems to be unable to resolve these language specific URLs (i.e. to identify url1 and url2 as two separate URLs/files to be downloaded). Instead, it seems to only download the last URL (so url2 in the example).