Fixes outdated IPv6 TODO on `getAddr`. (#2601)
Fixes outdated IPv6 TODO on `getAddr`. (#2601)

The VA's `getAddr` function prior to this commit had an outdated comment
& a pointer to a TODO for Boulder Issue #593. That issue has been closed
and bdns' `LookupHost` supports AAAA records now. This commit updates
the comment to match the current behaviour and removes the TODO.
jsha/boulder,jcjones/boulder,lucasallan/boulder,letsencrypt/boulder,ibukanov/boulder,ibukanov/boulder,ibukanov/boulder,lucasallan/boulder,jfrazelle/boulder,jfrazelle/boulder,jcjones/boulder,lucasallan/boulder,jcjones/boulder,jsha/boulder,jcjones/boulder,letsencrypt/boulder,jsha/boulder,bmw/boulder,jfrazelle/boulder,bmw/boulder,jfrazelle/boulder,letsencrypt/boulder,bmw/boulder