res_query: send error

[Rudloff]

DNS resolution works correctly when calling dnsproxy2 -l directly:

;; res_setoptions("debug", "env")..
;;	debug
;; res_nquerydomain(google.fr, <Nil>, 1, 1)
;; res_query(google.fr, 1, 1)
;; res_nmkquery(QUERY, google.fr, IN, A)
;; res_send()
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27940
;; flags: rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;;	google.fr, type = A, class = IN
;; Querying server (# 1) address = 8.8.8.8
;; new DG socket
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27940
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;;	google.fr, type = A, class = IN
google.fr.		4m59s IN A	216.58.209.227
216.58.209.227

But if fails when used in proxy mode:

;; res_nquerydomain(google.fr, <Nil>, 1, 1)
;; res_query(google.fr, 1, 1)
;; res_nmkquery(QUERY, google.fr, IN, A)
;; res_send()
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36674
;; flags: rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;;	google.fr, type = A, class = IN
;; res_query: send error