If you have no handlers for any zone CoreDNS would crash, this is very
*uncommon*, because it makes your server a bit unusable. Example config:
~~~
. {
    #forward . tls://9.9.9.9 8.8.8.8 {
    #    health_check 5s
    #    tls_servername dns.quad9.net
    #}
    pprof
    debug
}
~~~
It this does nothing and doesn't setup you plugin chain because pprof and
debug don't handle queries