audio/fasttracker2: Update to v1.09

Changes since v1.08:

v1.09 - 12.02.2020
- Fix: If a corrupt .XM doesn't contain all the sample data at the end of the
  file, try to load what is left instead of showing an "Out of memory!" message.
- Fix: Prevent upscaling factors higher than 2x on ARM devices. Fixes extreme
  slowdowns on Raspberry Pi 4 with 2k or higher resolution screens.
- The .MOD importer has been slightly improved for oldschool 15-sample formats
- The .S3M importer has been slightly improved for certain effect cases not
  compatible with FT2.
- Audio mixer: Internal voice volumes are now calculated with 256 times higher
  precision than FT2. Some other changes were also made to make sure the audio
  mixing is always done at max precision regardless of the "amp" setting in
  the config screen. These are changes that most people won't ever be able to
  hear, but the speed performance of the mixer is still the same, so why not.
- The audio dithering routine has now been improved (rectangular->triangular),
  and it's now enabled by default on a fresh configuration, or if you reset it.


(fox)