Log Message:
libopenmpt: update to 0.5.9.

### libopenmpt 0.5.9 (2021-05-16)

 *  `Makefile` `CONFIG=emscripten` does not pass linker options to the compiler
    any more, which caused latest Emscripten to issue warnings.

 *  The retrigger effect didn't work correctly for OPL instruments in some cases
    depending on the chosen output sample rate.
 *  S3M: Emulate IT short sample retrigger quirk in S3M files saved with
    Impulse Tracker and Schism Tracker.
 *  ProTracker 3.6 doesn't support sample swapping. It is now disabled when
    loading a ProTracker 3.6 IFF module.
 *  Some files with "hidden" garbage patterns were not played \ 
correctly since
    libopenmpt 0.5.3.
 *  MOD: E9x retrigger now works the same way as in ProTracker 2.
 *  MDL: Improve auto-vibrato accuracy.
 *  669: Reject files that contain any pattern tempo higher than 15.
 *  Reduce memory consumption of malformed XPK-compressed files.

 *  mpg123: Update to v1.27.2 (2021-05-08).