save media source in metadata typemap

src/main.rs

@@ -78,7 +78,6 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
                 songbird,
                 standby: Standby::new(),
                 guild_settings: Default::default(),
-                tracks: Default::default(),
             }),
         )
     };