Error binding multicast metatraffic port on macOS

[orecham]

The minimal examples fail on macOS with the following error after starting the second process of the publisher-subscriber pair:

thread 'main' panicked at dds/examples/best_effort_publisher.rs:23:10:
called `Result::unwrap()` on an `Err` value: Error("Address already in use (os error 48)")
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

This is presumably due to different behaviour on Linux and macOS (I have not tested on Linux myself yet but figured that these examples work there), as described here: https://stackoverflow.com/questions/51998042/macos-so-reuseaddr-so-reuseport-not-consistent-with-linux