get APP_CONFIG_KEY from parent app

[afanasevps]

Hello,
if we use init CORS in main app not work in subapp

  File aiohttp_cors/mixin.py", line 22, in get_request_config
    cors = request.app[APP_CONFIG_KEY]
  File aiohttp/web_app.py", line 104, in __getitem__
    return self._state[key]
KeyError: 'aiohttp_cors'

fix problem use config_dict https://docs.aiohttp.org/en/stable/web_reference.html#aiohttp.web.Request.config_dict

cors = request.config_dict[APP_CONFIG_KEY]

thanks!

[asvetlov]

Hi!
Good catch!
Would you mind working on Pull Request?

[afanasevps]

ok, sure i'll do PL

[afanasevps]

@asvetlov PL here - #220

[parikls]

Can anyone approve PR for this?