WARNING: Raspbian October 2021 release bullseye + unbound

@devs & @mods, shall I add a section?

Make sure the openresolv package doesnt configure unbound to function as a simple caching DNS forwarder instead of a recursive DNS resolver.
This mostly applies to newer distro's like Debian/Raspbian Bullseye.
Errors like "file not found" can be ignored:

sudo sed -i 's\^unbound_conf=\#unbound_conf=\g' /etc/resolvconf.conf

sudo rm -f /etc/unbound/unbound.conf.d/resolvconf_resolvers.conf

The unbound daemon gets restarted later in the guide.