about: add missing author + use https ring.cx

Change-Id: I0474b08c75ccd942b0150943c46f009d1a0877da
Reviewed-by: Philippe Gorley <philippe.gorley@savoirfairelinux.com>
diff --git a/Credits.rtf b/Credits.rtf
index 21b466e..02a2a4e 100644
--- a/Credits.rtf
+++ b/Credits.rtf
@@ -7,7 +7,7 @@
 
 \f0\i\fs24 \cf0 \
 \pard\tx566\tx1133\tx1700\tx2267\tx2834\tx3401\tx3968\tx4535\tx5102\tx5669\tx6236\tx6803\pardirnatural\qc\partightenfactor0
-{\field{\*\fldinst{HYPERLINK "http://ring.cx/"}}{\fldrslt \cf0 http://ring.cx/}}\
+{\field{\*\fldinst{HYPERLINK "https://ring.cx/"}}{\fldrslt \cf0 https://ring.cx/}}\
 \
 \pard\tx566\tx1133\tx1700\tx2267\tx2834\tx3401\tx3968\tx4535\tx5102\tx5669\tx6236\tx6803\pardirnatural\qc\partightenfactor0
 
@@ -27,6 +27,7 @@
 Emmanuel Lepage-Vall\'e9e\
 Fr\'e9d\'e9ric Guimont\
 Guillaume Roguez\
+Hadrien De Sousa\
 Julien Grossholtz\
 Kateryna Kostiuk\
 Lo\'efc Siret\