DOC: stop referencing the slow git repository in the README

git.1wt.eu is painfully slow and some people experience issues with
it. Better hide it and only advertise git.haproxy.org which is mirrored
on a faster server.

Also replace haproxy.1wt.eu with www.haproxy.org in the download URL
which appears in the stats page.
diff --git a/README b/README
index a5085fd..4f39df8 100644
--- a/README
+++ b/README
@@ -338,7 +338,7 @@
 significant code contributions (features, fixes), but also time or money
 donations :
 
-                        http://haproxy.1wt.eu/contrib.html
+                        http://www.haproxy.org/contrib.html
 
 Note to contributors: it's very handy when patches comes with a properly
 formated subject. There are 3 criteria of particular importance in any patch :
@@ -526,12 +526,8 @@
 definitely help you contribute quality code and take other people's feedback
 in consideration. In order to clone the HAProxy Git repository :
 
-    $ git clone http://git.1wt.eu/git/haproxy-1.4.git    (stable 1.4)
-    $ git clone http://git.1wt.eu/git/haproxy.git/       (development)
-
-The site above is slow, a faster mirror is maintained up to date here :
-
-    $ git clone http://master.formilux.org/git/people/willy/haproxy.git/
+    $ git clone http://git.haproxy.org/git/haproxy-1.4.git    (stable 1.4)
+    $ git clone http://git.haproxy.org/git/haproxy.git/       (development)
 
 If you decide to use Git for your developments, then your commit messages will
 have the subject line in the format described above, then the whole description