[demo] support English

app.py

@@ -30,6 +30,7 @@ def recognition(audio, lang='CN'):
     y, _ = librosa.load(audio, sr=16000)
     # NOTE: model supports 16k sample_rate
     y = (y * (1 << 15)).astype("int16")
+    global cur_lang
     if lang == 'CN':
         if cur_lang != lang:
             del decoder