Merge pull request #354 from mirage/fix-miou

Use String.get_uint_16 instead of get_int_16 which leads to a bad id for the packet

Author: hannesm

miou/client/dns_client_miou_unix.ml

@@ -139,7 +139,7 @@ module Transport = struct
     if String.length str > 4 then begin
       match fd with
       | `Tls fd ->
-        let id = String.get_int16_be str 2 in
+        let id = String.get_uint16_be str 2 in
         send_recv_tls ~timeout ~id fd str 
       | `Udp fd | `Tcp fd ->
           let fd = Miou_unix.to_file_descr fd in