make Prot to method (#3500)
make Prot to method (#3500)

Signed-off-by: zouyee <6930cd8d7eab0b52cb34a0610ba7cd21fe073fc5@cmss.chinamobile.com>
yongtang/coredns,johnbelamaric/coredns,coredns/coredns,chrisohaver/coredns,miekg/coredns,miekg/coredns,johnbelamaric/coredns