Add Walloon translator

(cherry picked from commit 7dbad05d)
Signed-off-by: Christophe Mutricy <xtophe@videolan.org>

THANKS

@@ -127,6 +127,7 @@ Frank Chao <frank0624 at gmail.com> - Chinese Traditional translation
 Frans van Veen <f.m.j.c.vanveen at student.hhs.nl> - Mozilla plugin toolbar
 Fumio Nakayama <endymion at ca2.so-net.ne.jp> - Japanese translation
 Gabor Kelemen <kelemeng at gnome dot hu> - Hungarian translation
+Gaëtan Rousseaux <garousseau@voo.be> - Walloon translation
 Geoffrey Roussel <meka321 at hotmail dot com> - Christmas easter egg Artwork
 Geoffroy Couprie <geo dot couprie -- gmail # com> - Podcast fix
 Georgi Chorbadzhiyski <gf at unixsol dot org> - HTTP access error handling fix, ASF output patches.