bug#22789: 25.1.50; In last master build https connections stop working

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: José L. Doménech <j_l_domenech@yahoo.com>,
>   22789@debbugs.gnu.org
> Date: Thu, 25 Feb 2016 11:02:51 +1100
> 
> If you eval the following, does anything show up in the "*foo*" buffer?
> 
> (setq proc
> (make-network-process :name "foo"
>                     :buffer (get-buffer-create "*foo*")
>                     :host "imap.gmail.com"
>                     :service 993
>                     :nowait t
>                     :tls-parameters
>                     (cons 'gnutls-x509pki
>                           (gnutls-boot-parameters
>                            :type 'gnutls-x509pki
>                            :hostname "imap.gmail.com"))))

I see there only this:

  Process foo connect

> * OK Gimap ready for requests from 60.225.211.161 qr7mb410250987iec
> 
> should appear.  Also, after evaling that, what does
> 
> (process-status proc)
> 
> say?  It should say "connect" for a little bit, and then "open"...

It stays "connect" forever.  But "netstat" doesn't show any
connections to that server, AFAICT.  I think the connection simply
doesn't begin.

Btw, one other difference of the Windows build, this time wrt GnuTLS,
is that on Windows we instruct GnuTLS to use our own pull and push
functions, see gnutls.c around line 450.  The functions themselves are
defined in w32.c, at the end.