replaced the self.mode for __init__ as None instead of chatting

app.py

@@ -58,13 +58,13 @@ refiner.to('cuda')
 
 class ModeManager:
     def __init__(self):
-        self.mode = ""
+        self.mode = None
 
     def set_mode(self, mode):
         self.mode = mode
 
     def get_mode(self):
-        return self.mode
+        return self.mode if self.mode is not None else "chatting"
 
 mode_manager = ModeManager()