Static thumbnails do not work anymore

Previously, thumbnails were available for each score at http://static.musescore.com/{id}/{secret}/thumb.png, e.g. http://static.musescore.com/1913/9425027ede/thumb.png as is also stated in the documentation: http://developers.musescore.com/#score-files-urls

However, this does not seem to be working anymore, as you can tell by clicking on the above example link.

Would it be possible to update the documentation to state the new thumbnail URL? My telegram bot at https://telegram.me/musescorebot needs those thumbnails to easily identify scores when searching.