dont handle missing rr with nxdomain

This reverts commit 00a82aca87.

internal/authoritative.go

@@ -121,7 +121,15 @@ func handleRequest(w dns.ResponseWriter, r *dns.Msg, zone zoneView) {
 	}
 
 	if len(m.Answer) == 0 {
-		m.SetRcode(m, dns.RcodeNameError)
+		var soa dns.RR
+		for _, v := range zone.rr[dns.TypeSOA] {
+			if len(v) == 1 {
+				soa = v[0]
+			}
+		}
+		if soa != nil {
+			m.Extra = append(m.Extra, soa)
+		}
 	}
 
 	w.WriteMsg(m)