gmid ended up printing two slashes between the hostname and the path when logging the request IRI.

Currently dogfooding this patch at gemini.sgregoratto.me. To test, run the following command and look for the "OCSP response" header: openssl s_client -connect "gemini.sgregoratto.me:1965" -status

the error path needs an initialized bufferevent too, otherwise it'll crash when trying to write the response. This moves the initialisation early, right after the tls_handshake. Another option would be to initialise it in do_accept, but that may be too early.

ECONNABORTED is returned if a connections gets aborted after being queued before the accept(2). I had some cases of accept: Software caused connection abort on FreeBSD, this should avoid that.