add dvb channels list .conf as filetype.

(see demux/playlist/dvb. mplayer's std being channels.conf)
(cherry picked from commit 05b1efd02cf98f32b2022ff61ebc2f41a83dfbfb)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

include/vlc_interface.h

@@ -228,7 +228,7 @@ typedef enum vlc_dialog {
                          "*.ogg;*.ogm;*.ogv;*.ogx;*.ps;" \
                          "*.rec;*.rm;*.rmvb;*.tod;*.ts;*.tts;*.vob;*.vro;*.webm;*.wmv"
 
-#define EXTENSIONS_PLAYLIST "*.asx;*.b4s;*.cue;*.ifo;*.m3u;*.m3u8;*.pls;*.ram;*.rar;*.sdp;*.vlc;*.xspf;*.zip"
+#define EXTENSIONS_PLAYLIST "*.asx;*.b4s;*.cue;*.ifo;*.m3u;*.m3u8;*.pls;*.ram;*.rar;*.sdp;*.vlc;*.xspf;*.zip;*.conf"
 
 #define EXTENSIONS_MEDIA EXTENSIONS_VIDEO ";" EXTENSIONS_AUDIO ";" \
                           EXTENSIONS_PLAYLIST