RFC 6066 states that IP literals are not permitted in "HostName" for a

RFC 6066 states that IP literals are not permitted in "HostName" for a
TLS Server Name extension, however seemingly several clients (including
Python, Ruby and Safari) violate the RFC. Given that this is a fairly
widespread issue, if we receive a TLS Server Name extension that contains
an IP literal, pretend that we did not receive the extension rather than
causing a handshake failure.

Issue raised by jsg@

ok jsg@