audio/musicpd: Update to 0.24.3

This is a major upgrade to the 0.24.x branch of MPD. For most users it
is expected to just work[tm], but a lot has changed behind the scenes.
Details:

• See changelog since 0.23.17, see https://raw.githubusercontent.com/MusicPlayerDaemon/MPD/v0.24.3/NEWS
• The SOUNDCLOUD and YAJL OPTIONs have been retired upstream and in the port.