Prevents OSX firewall
allow-this-application-to-accept-inbound-connections
permission popups and is generally safer.
To prevent binding to 127.0.0.1, set self.bind_to_localhost_only =
False.
Backport of core PR12482
https://github.com/bitcoin/bitcoin/pull/12482/files
Depends on D3090 (prevent failure in `abc-high_priority_transaction`, see the CI build log).