Hi,
After direct contact with the author, I corrected the information about
author and license in this commit:
https://sourceforge.net/p/supertuxkart/code/16762/
Also note that source files (the .mod file and lossless .wav file) are
available in our media repo:
https://sourceforge.net/p/supertuxkart/code/HEAD/tree/media/trunk/music/mods/
More information:
http://forum.freegamedev.net/viewtopic.php?f=17&t=6562
https://github.com/supertuxkart/stk-code/issues/2577
I hope that this should be enough to fix this issue.
Regards,
Deve