Unneeded nginx customisation recipes

[cameronbourgeois]

There are some custom modules that aren't needed by Opsworks as you can customise nginx in your stack json like so:

{
  "nginx": {
    "client_max_body_size": "200m",
    "proxy_read_timeout": "300",
    "proxy_send_timeout": "300"
  },
  "unicorn": {
    "timeout": "300"
  }
}

[cameronbourgeois]

I propose removing the following:

custom_nginx
custom_nginx_10mb_request_limit
custom_nginx_300s_proxy_timeout
custom_unicorn
nginx_large_uploads