Add openssh patch to suppress errors on XP

Winsock IP_TOS option is silently ignored on Windows 7.
http://blogs.msdn.com/b/wndp/archive/2006/07/05/657196.aspx

IP_TOS option causes an error on Windows XP.
https://groups.google.com/forum/#!topic/msysgit/2VEyHhOXEps
Merge pull request #226 from shirosaki/fix_openssh

Add openssh patch to suppress errors on XP