Merge pull request #7115 from rgacogne/dnsdist-secpoll

dnsdist: Add security polling

diff --cc pdns/dnsdist-console.cc
Simple merge

diff --cc pdns/dnsdist-lua.cc
Simple merge

diff --cc pdns/dnsdist.hh
Simple merge

diff --cc pdns/dnsdistdist/docs/reference/config.rst
Simple merge