Vladimír Čunát authored Dec 07, 2018 and Petr Špaček committed Dec 14, 2018

- It was too aggressive.  Example I ran into: we have glue address
  in qry->ns but we want to find authoritative record by asking the NS.
- The anti-cycling measures are probably not perfect yet,
  but they seem to be fine enough and this commit seems
  very unlikely to make anything worse in practice.