audio/qsynth: Update to 0.5.1
- Use the upstream release tarballs with a pregenerated configure, etc.
- Drop the seemingly unnecessary post-configure which was added in r308039 but with no reason given for it in the associated PR or log
- Update --help output to mention the sndio drivers too
- Patch audio driver list in the man pages too
- Follow WWW redirect
- Take maintainership
Changes: https://qsynth.sourceforge.io/qsynth-downloads.html