dns/dnsdist: Update to 2.1.0
Changelog: https://www.dnsdist.org/changelog.html#change-2.1.0
PR: 296456
Reported by: Jordan Ostreff <jordan@ostreff.info> (initial patch),
Ralf van der Enden <tremere@cainites.net> (maintainer, committed patch)
(cherry picked from commit d4dec80c2c0412548c8a7cbd137862df0193aa08)