Update app.py

app.py

@@ -313,7 +313,7 @@ def inference(audio):
 	audio = upload_audio(contents,sample_rate=16000)
 	est_ns = inference_model(audio)
 	note_seq.sequence_proto_to_midi_file(est_ns, './transcribed.mid')
-    return "./transcribed.mid"
+	return './transcribed.mid'
 
 title = "MT3"
 description = "MT3：多任务多音轨音乐转录的 Gradio 演示。要使用它，只需上传音频文件，或点击示例以查看效果。更多信息请参阅下面的链接。"