libxml2.recipe: Fix download URL, broken https
libxml2.recipe: Fix download URL, broken https

nirbheek/cerbero,GStreamer/cerbero,atsushieno/cerbero,atsushieno/cerbero,atsushieno/cerbero,GStreamer/cerbero,nirbheek/cerbero,fluendo/cerbero,nirbheek/cerbero,centricular/cerbero,centricular/cerbero,centricular/cerbero,fluendo/cerbero,centricular/cerbero,GStreamer/cerbero,atsushieno/cerbero,centricular/cerbero,GStreamer/cerbero,fluendo/cerbero,nirbheek/cerbero,fluendo/cerbero,fluendo/cerbero,atsushieno/cerbero,GStreamer/cerbero