Log Message:
libopenmpt: update to 0.6.1.

### libopenmpt 0.6.1 (2022-01-30)

 *  [**Bug**] Linking libmpg123 no longer fails on OpenBSD.
 *  [**Bug**] Possible hang with malformed DMF, DSM, MED, MUS, OKT and SymMOD
    files containing 65536 or more patterns when destroying the module.
 *  [**Bug**] Avoid NaNs and infinite values with custom tunings and in the
    I3DL2Reverb plugin.

 *  The letter "z" is now evaluated in fixed MIDI macros (Z80...ZFF) \ 
the same
    way as in Impulse Tracker.
 *  MOD: Loosened VBlank timing heuristics so that "frame of mind" by \ 
Dascon
    plays correctly.
 *  MOD: Validate the contents of "hidden" patterns beyond the end of \ 
the order
    list when the file size matches the expected size when only taken \ 
"official"
    patterns into account. This fixes Shofixti Ditty.mod from Star Control 2
    while keeping other (partly broken) modules working.
 *  MED: Command 20 (reverse sample) is now only applied when it's next to a
    note.
 *  S3M: Introducing the "Send OPL key-off when triggering notes" \ 
compatibility
    setting broke retrigger for OPL notes again (they retriggered rather than
    not retriggering).
 *  S3M: Retriggering a note no longer resets its pitch after a portamento.
 *  S3M: Partially implement retrigger behaviour for stopped notes in
    SoundBlaster mode: Like in IT, it is not possible to retrigger a sample that
    has already stopped playing.
 *  DIGI: Improve compatibility with E3x reverse sample command.
 *  DSym: Tempos < 32 were treated as tempo slides.
 *  SymMOD: Key-off command was not implemented properly.