add missing external prototype

git-svn-id: svn+ssh://svn.savannah.nongnu.org/linphone/trunk@386 3f6dc0c8-ddfe-455d-9043-3cd528dc4637

linphone/mediastreamer2/build/win32native/mediastreamer2.def

@@ -22,6 +22,7 @@ EXPORTS
 	ms_filter_new_from_name
 	ms_filter_set_notify_callback
 	
+	ms_snd_card_manager_register_desc
 	ms_snd_card_create_reader
 	ms_snd_card_create_writer
 	ms_snd_card_get_name