libopenmpt: update to 0.5.14.

### libopenmpt 0.5.14 (2021-12-05)

*  [**Sec**] Possible out-of-bounds read in Chorus plugin with NaN plugin
    parameters. Most implementations of the "fast math" compiler optimizations
    will prevent this crash but it is not guaranteed. (r16096)

*  [**Bug**] Fixed undefined behaviour with custom tunings found with ubsan.

*  OPL: Improved channel allocation strategy when there are lots of faded-out
    notes.
*  MOD: Digital Tracker MODs have four unknown bytes right after the magic
    bytes which seem to be ignored even by Digital Tracker itself. Just skip
    over them.
*  The logic when to turn off the resonant filter was broken in some edge cases
    since libopenmpt 0.5.1.
*  IMF: Implemented XE1-XE3 commands, which disable individual envelopes.
    Command Nxy (cutoff slide + resonance) is now also partially supported
    (only resonance for now).
*  IMF: Filter envelopes were upside down.
*  MTM: Omitting pattern loading through the load.skip_patterns ctl caused
    sample data to be corrupted.
*  S3M: Ignore O00 commands in files created with Scream Tracker 3.00 and 3.01,
    as this command only gained effect memory in version 3.03.
*  STM: Use S3M-like sample swap behaviour.
*  XM: Disable arpeggio quirk for XMs made with Skale Tracker.
    Fixes KAPTENFL.XM.

*  miniz: Update to v2.2.0 (2021-06-27).
*  minimp3: Update to commit 50d2aaf360a53653b718fead8e258d654c3a7e41
    (2021-11-27).

(fcambus)