http://bugs.winehq.org/show_bug.cgi?id=35828
--- Comment #7 from Hans Leidekker hans@meelstraat.net --- This is an issue with the certificate used on their server. The root CA for this certificate is GTE CyberTrust Global Root which has been removed from the system CA bundle, on Debian at least.
Mozilla's bundle still has it and if I patch crypt32 to prefer that the error message disappears.