DEVELOPERS: fix Guillaume Chaye's entry

Commit f78280bf262c ("package/sane-airscan: new package") added a new entry
in DEVELOPERS, but forgot to add the email address.  Fix that.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

DEVELOPERS

@@ -1361,7 +1361,7 @@ F:	package/python-rpi-ws281x/
 F:	package/python-wtforms/
 F:	package/rpi-rgb-led-matrix/
 
-N:	Guillaume Chaye
+N:	Guillaume Chaye <guillaume.chaye@zeetim.com>
 F:	package/sane-airscan/
 
 N:	Guillaume William Brs <guillaume.bressaix@gmail.com>