Remove version and default bridge network

[emfox]

1. 'version' is obsolete.
2. Connect to default bridge is not recommended, just let docker create a 'nginx-proxy_default' bridge by default, or define named network.

[emfox]

"The default bridge network is considered a legacy detail of Docker and is not recommended for production use. " from official documentation:
https://docs.docker.com/engine/network/drivers/bridge/#use-the-default-bridge-network

[buchdag]

Thanks @emfox 👍