document that

src/subsonic.rs

@@ -204,6 +204,11 @@ impl Client {
                 })
             }
 
+            // this Result is only an error if the main loop future was cancelled
+            // therefore it's safe to just drop it
+            // note that in general its fine not to cancel the tokio task when its corresponding
+            // mainloop task is dropped, since eg for song thumbnails there's already a semaphore
+            // limiting concurrent requests
             let _ = sender.send(perform(future.await).await).await;
         });