FreeBSD jail raises OSError[errno.EPROTONOSUPPORT] in get_localhost() if IPv6 support is missing

[Astranox]

When updating mailman a few days ago starting it returned an error message, namely "OSError: [Errno 43] Protocol not supported".

This is errno.EPROTONOSUPPORT on FreeBSD in jails without IPv6 support.

There was also a similar issue #244, which was fixed in pull requests #248 and #250 by adding support for errno.EAFNOSUPPORT.

Maybe this could also be added to aiosmtpd/controller.py:43 so that the line reads NO = {errno.EADDRNOTAVAIL, errno.EAFNOSUPPORT, errno.EPROTONOSUPPORT}

[pepoluan]

Thanks! I didn't have a FreeBSD system with me when writing that.

I'll see what I can do.