sslutil: restore old behavior not requiring a hostname argument (issue5210) This effectively backs out changeset 1fde84d42f9c. The http library behind ui.http2=true isn't specifying the hostname. It is the day before the expected 3.8 release and we don't want to ship a regression. I'll try to restore this requirement in the 3.9 release cycle as part of planned improvements to Mercurial's SSL/TLS interactions.