dshow: add options for allowing filter popup configuration dialogs to be presented to the user

Signed-off-by: rogerdpack <rogerpack2005@gmail.com>

libavdevice/dshow_capture.h

@@ -298,6 +298,7 @@ struct dshow_ctx {
     char *audio_pin_name;
     int   show_video_device_dialog;
     int   show_audio_device_dialog;
+    int   show_crossbar_connection_dialog;
 
     IBaseFilter *device_filter[2];
     IPin        *device_pin[2];