chore(tests): add support for missing localhost in DNS

[aduh95]

If for whatever reason, DNS cannot retrieve localhost, fallback to the default unspecified address (i.e. :: or 0.0.0.0).

[MikeMcC399]

@aduh95

Your PR has hit the CI-failure issue described in #813. Since the runner version is random, you may be able to get CI to succeed by re-running, and hoping that the job is allocated an old runner version.

I've just submitted #817 as a mitigation.