Important fix (sshd && binding). Portable version only.

[Kevin Steves]

On Sat, 17 Feb 2001, Arkadiusz Miskiewicz wrote:
: > because it skips displaying valid error messages,
: > and also displays invalid error messages; in this case port 22 is
: > already bound:
: so now remove all ListenAddress directives from config and run sshd
: on ipv6 ready kernel... It will try to bind on :: and then
: bind on 0.0.0.0. If you remove af_next check then second bind will
: cause error message but this is _proper_ configuration and _proper_ bind
: behavoiur at least on Linux. Problem exist due to different ipv6 implementations/rfc
: interpretations. You need to choose between geting error even on proper configurations
: or not showing it in some cases.

i don't have ipv6 configs to experiment with, but i do not agree with a
change that drops valid error messages and logs erroneous success
messages.

i would like to sync with openbsd. can you come up with a patch that
would be accepted in their tree that will log acceptably on all
platforms?