title: jwilder/nginx-proxy points to the nginx welcome screen
body: <p>I am trying to use the <a href="https://github.com/jwilder/nginx-proxy" rel="nofollow">nginx-proxy</a> docker container, but if I point to my domain with no subdomain (mydomain.com) then I just get the welcome page. I am using Docker-Compose and my .yml file looks like this:</p>
  
  <pre><code>proxy:
    image: jwilder/nginx-proxy
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro
    environment:
      DEFAULT_HOST: mydomain.com
    ports:
      - "80:80"
  
  frontend:
    image: julienvincent/nginx:react
    ports:
      - "8000:80"
    expose:
       - "80"
    volumes:
       - frontend/src/build:/data/www
    environment:
      VIRTUAL_HOST: www.mydomain.com, mydomain.com
  </code></pre>
  
  <p>Is this an error in my configuration?</p>