DEVELOPERS: remove Bernd Kuhls from package/x11r7/

Remove packages which are no longer runtime-tested here.

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>

DEVELOPERS

@@ -471,7 +471,6 @@ F:	package/vdr-plugin-vnsiserver/
 F:	package/vlc/
 F:	package/vnstat/
 F:	package/waylandpp/
-F:	package/x11r7/
 F:	package/x264/
 F:	package/x265/
 F:	package/xmrig/