Link to SSO documentation in web password update field

Hello,

attached is a simple patch that adds a link to
http://wiki.debian.org/DebianSingleSignOn to web password update field.

Can you please apply it and push it to production?

Ciao,

Enrico

--
GPG key: 4096R/E7AD5568 2009-05-08 Enrico Zini <enrico@enricozini.org>

From 21da63edc068b1e717c6f48d80bed17178c96e23 Mon Sep 17 00:00:00 2001
From: Enrico Zini <enrico@enricozini.org>
Date: Sun, 25 Nov 2012 11:08:53 +0100
Subject: [PATCH] Added link to single signon documentation

Signed-off-by: Martin Zobel-Helas <zobel@debian.org>