Fix test

--- python-aiohttp-3.8.4.orig/tests/test_web_urldispatcher.py
+++ python-aiohttp-3.8.4/tests/test_web_urldispatcher.py
@@ -13,6 +13,7 @@ import pytest
 import yarl
 
 from aiohttp import abc, web
+from aiohttp.pytest_plugin import AiohttpClient
 from aiohttp.web_urldispatcher import SystemRoute