openssh: update, fix CVE-2014-2653 by a Debian patch

(cherry picked from commit e50a76a4693a9f64c028e47c336b68cf36a50e7b)

I was lazy to do any backporting, so I took the expression from master.
It looked like there were some more CVEs fixed in between.

Conflicts:
	pkgs/tools/networking/openssh/default.nix