doc: replace a couple of broken gmane links

Replace a couple of broken links to gmane with links to other
archives. See commit 54471fdcc3 ("README: replace gmane link with
public-inbox", 2016-12-15) for prior art.

With this change there's still 4 references left in the code:

    $ git grep -E '(article|thread)\.gmane.org' -- |grep -v RelNotes|wc -l
    4

I couldn't find alternative links for those.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index a4191aa..2248cf7 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -24,7 +24,7 @@
 
    "Once it _is_ in the tree, it's not really worth the patch noise to
    go and fix it up."
-   Cf. http://article.gmane.org/gmane.linux.kernel/943020
+   Cf. http://lkml.iu.edu/hypermail/linux/kernel/1001.3/01069.html
 
 Make your code readable and sensible, and don't try to be clever.