Just ran into this one, but with apache, so a little followup - this
was a case where you're trying to establish an SSL connection, and
other side expects a regular http request. It had nothing to do with
the actual port or self-signedness of the cert - just mismatching the
virtualhost directives so the https ended up being served with the
wrong entry. So, if you get this error, try http:// instead of https://
(you can't have both http and https on the same port anyway) or fiddle
with https settings.