MINOR: dns: update record dname matching for SRV query types

MINOR: dns: update record dname matching for SRV query types

DNS response for SRV queries look like this:
- query dname looks like '_http._tcp.red.default.svc.cluster.local'
- answer record dname looks like
  '3336633266663038.red.default.svc.cluster.local.'

Of course, it never matches... and it triggers many false positive in
the current code (which is suitable for A/AAAA/CNAME).

This patch simply ignores this dname matching in the case of SRV query
type.