musicpd: update to 0.23.9.

ver 0.23.9 (2022/08/18)
* input
  - cdio_paranoia: add options "mode" and "skip"
* decoder
  - ffmpeg: support FFmpeg 5.1
* filter
  - replay gain: fix delayed volume display with handler=mixer
* output
  - pipewire: set app icon
* fix bogus volume levels with multiple partitions
* improve iconv detection
* macOS: fix macOS 10 build problem (0.23.8 regression)
* Android
  - load mpd.conf from app data directory

(wiz)