Fixed import issue

server.py

@@ -36,6 +36,7 @@ import urllib.request
 from pathlib import Path
 from gradio import Server
 from typing import Any, Dict, List, Optional
+from fastapi.responses import HTMLResponse
 from fastapi.staticfiles import StaticFiles
 from fastapi.middleware.cors import CORSMiddleware
 from dotenv import load_dotenv