Similar to how we summarize and inform when all connection errors
are due to broken TLS, recognize and inform when all connection
errors are due to a source_address that cannot be bound due to
the address not being plumbed on the system. This does not
include other reasons that `bind(2)` can fail, just the case
where the address is not present.
Add an integration test to capture the error message for
that situation, for easier future reference.
Wez Furlong