Possibel license violation from commercial product. Pro-actively
removing the files.
See Flightgear-devel thread "License violation in the FGAddon B767"
September 24th, 2020.
https://sourceforge.net/p/flightgear/mailman/flightgear-devel/thread/1537A19C-D4CE-4C25-A81D-F9B1D3AAF903%40flightgear.org/#msg37115530
