fix async with in TestClient.ws_connect (#2528)
fix async with in TestClient.ws_connect (#2528)

* WIP fix#2525

* Update test_utils.py

arthurdarcet/aiohttp,pfreixes/aiohttp,arthurdarcet/aiohttp,KeepSafe/aiohttp,rutsky/aiohttp,KeepSafe/aiohttp,pfreixes/aiohttp,KeepSafe/aiohttp,hellysmile/aiohttp,hellysmile/aiohttp,arthurdarcet/aiohttp,rutsky/aiohttp,rutsky/aiohttp