gnu: audio: Use HTTPS for kokkinizita.linuxaudio.org home pages.

* gnu/packages/audio.scm (clalsadrv, amb-plugins, mcp-plugins, rev-plugins)
(fil-plugins, ste-plugins, vco-plugins, wah-plugins, g2reverb)
(zita-convolver, zita-resampler, zita-alsa-pcmi)[home-page]: Use HTTPS.