[rbldnsd] Disabling ipv6-specific tests

[Michael Orlitzky]

On 08/01/2013 06:40 PM, Jeff Dairiki wrote:
> 
> Oof.  Who knew that you could create an ipv6 socket without has_ipv6?
> I guess I should have listened to you in the first place...
> 
> Hopefully this fixes it:
>    https://github.com/dairiki/rbldnsd/commit/087e1a1
> 
> Jeff
> 

I think we have a winner. I just ran through all 8 combinations and the
ipv6 tests are properly run/skipped.

Now there's just the minor issue where everything goes to hell when
daemon_addr='localhost'. I don't think it can simply be changed to
'127.0.0.1', since there are people running with only ipv6. I like the
idea of checking for getaddrinfo and using it if possible, but I'm not
the one doing the work, so if there's an easier way to get just the
tests working I'll take it.