fix error msg again

app.py

@@ -16,8 +16,7 @@ CONVERSION_SCRIPT = "convert_lora_to_gguf.py"
 
 def process_model(peft_model_id: str, q_method: str, private_repo, oauth_token: gr.OAuthToken | None):
     if oauth_token is None or oauth_token.token is None:
-        gr.Error("You must be logged in to use GGUF-my-lora")
-        raise ValueError("You must be logged in to use GGUF-my-lora")
+        raise gr.Error("You must be logged in to use GGUF-my-lora")
     model_name = peft_model_id.split('/')[-1]
     gguf_output_name = f"{model_name}-{q_method.lower()}.gguf"