Fixes#4627.
AcousticBrainz is shutting down as of early 2023. Deprecate the absubmit
plugin and update the acousticbrainz plugin to require configuration of
an AcousticBrainz server instance.
*All* URLs were checked manually, but only once per domain!
I mostly concerned myself with URLs in documentation rather than source
code because the latter may or may not have impactful changes, while the
former should be straight forward.
Changes in addition to simply adding an s:
- changed pip and pypi references as their location has changed
- MPoD (iOS app) url redirects to Regelian, so I replaced those
- updated homebrew references
Notable observations:
- beets.io does have HTTPS set up properly (via gh-pages)
- beatport.py uses the old HTTP url for beatport
- as does lyrics.py for lyrics.wikia.com
- https://tomahawk-player.org/ expired long ago, but the http page
redirects to https regardless
- none of the sourceforge subdomains have https (in 2019!)
