[PATCH for-stable] docs: fix broken reference

[Thomas De Schampheleire]

# HG changeset patch
# User Thomas De Schampheleire <thomas.de.schampheleire at gmail.com>
# Date 1499941561 -7200
#      Thu Jul 13 12:26:01 2017 +0200
# Branch stable
# Node ID 4f0587e7623ceeb19fa32113c2b1a7a3623b6e00
# Parent  5dde581f703f43a97fe92ee3728cec67897d0380
docs: fix broken reference

diff --git a/docs/installation_iis.rst b/docs/installation_iis.rst
--- a/docs/installation_iis.rst
+++ b/docs/installation_iis.rst
@@ -126,4 +126,4 @@ application itself) that are uncaught, w
 traces, making it a lot easier to identify issues.
 
 
-.. _hgssoauthenticatio: https://bitbucket.org/domruf/hgssoauthentication
+.. _hgssoauthentication: https://bitbucket.org/domruf/hgssoauthentication