Fix duplicate import in app.py

app.py

@@ -6,7 +6,7 @@ from typing import List, Optional, Dict, Any
 from contextlib import asynccontextmanager
 
 import torch
-from transformers import AutoTokenizer, AutoModelForCausalLM, AutoModelForCausalLM, BitsAndBytesConfig
+from transformers import AutoTokenizer, AutoModelForCausalLM, AutoModelForSeq2SeqLM, BitsAndBytesConfig
 import uvicorn
 from fastapi import FastAPI, HTTPException, BackgroundTasks
 from fastapi.middleware.cors import CORSMiddleware