Merge pull request #9669 from Habbie/pdns.conf-primary-secondary

auth pdns.conf, pdnsutil, pdns_control: modern aliases for master/slave

diff --cc .github/actions/spell-check/expect.txt
Simple merge

diff --cc docs/modes-of-operation.rst
Simple merge

diff --cc docs/settings.rst
Simple merge

diff --cc docs/upgrading.rst
Simple merge

diff --cc pdns/common_startup.cc
Simple merge

diff --cc pdns/packethandler.cc
Simple merge

diff --cc pdns/pdnsutil.cc
Simple merge