pkg/response: add extra test for impossible msg (#2727)
pkg/response: add extra test for impossible msg (#2727)

Add another test case for impossible DNS messages which should not be
cached. This adds a check for a message that denies its own existence.

Fixes #2724.

Signed-off-by: Miek Gieben <00b357f94cf3a1145a32703fb42e2d80418ab806@miek.nl>
miekg/coredns,ii/coredns,ii/coredns,johnbelamaric/coredns,yongtang/coredns,johnbelamaric/coredns,miekg/coredns,coredns/coredns,chrisohaver/coredns