[niepce] README: remove dead mailing list link

[Hubert Figuière <hub src gnome org>]

commit 41fb76772d7a36732f619b7ad7e64a09368c5843
Author: Hubert Figuière <hub figuiere net>
Date:   Sun Nov 25 22:39:13 2018 -0500

    README: remove dead mailing list link

 README | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)
---
diff --git a/README b/README
index 3ea5e8c..420378c 100644
--- a/README
+++ b/README
@@ -64,9 +64,4 @@ https://wiki.gnome.org/Apps/Niepce
 IRC
 ---
 
-#niepce on irc.gnome.org
-
-Mailing list
-------------
-
-https://mail.gna.org/listinfo/niepce-devel/
\ No newline at end of file
+#niepce on irc.gnome.org
\ No newline at end of file