pass auto for auto language detection

STT/whisper_stt_handler.py

@@ -40,7 +40,7 @@ class WhisperSTTHandler(BaseHandler):
         self.torch_dtype = getattr(torch, torch_dtype)
         self.compile_mode = compile_mode
         self.gen_kwargs = gen_kwargs
-        if language == 'None':
+        if language == 'auto':
             language = None
         self.last_language = language
         if self.last_language is not None:

arguments_classes/whisper_stt_arguments.py

@@ -58,7 +58,7 @@ class WhisperSTTHandlerArguments:
             "help": """The language for the conversation. 
             Choose between 'en' (english), 'fr' (french), 'es' (spanish), 
             'zh' (chinese), 'ko' (korean), 'ja' (japanese), or 'None'.
-            If using None, the language is automatically detected and can
+            If using 'auto', the language is automatically detected and can
             change during the conversation. Default is 'en'."""
         },
     )