reload not working for official quickstart sample on windows

1111.py
```
from aiohttp import web

async def hello(request):
    return web.Response(text="Hello, world")

app = web.Application()
app.add_routes([web.get('/', hello)])
web.run_app(app)
```
adev runserver 1111.py

then:
modify "Hello, world"

refresh 127.0.0.1, noting change.