Resolve voice address once instead of repeatedly

src/voice.rs

@@ -194,7 +194,13 @@ fn voice_thread(
  let udp = try!(UdpSocket::bind("0.0.0.0:0"));
  let mut bytes = [0; 4];
  try!(Cursor::new(&mut bytes[..]).write_u32::<BigEndian>(ssrc));
- try!(udp.send_to(&bytes, (&endpoint[..], port)));
+ let destination = {
+ use std::net::ToSocketAddrs;
+ try!(try!((&endpoint[..], port).to_socket_addrs())
+ .next()
+ .ok_or(Error::Other("Failed to resolve voice hostname")))
+ };
+ try!(udp.send_to(&bytes, destination));
 
  // receive the response to the identification to get port and address info
  let mut bytes = [0; 256];
@@ -308,7 +314,7 @@ fn voice_thread(
 
  // encode the audio data and transmit it
  let len = opus.encode(&audio_buffer, &mut packet[HEADER_LEN..]).expect("failed encode");
- try!(udp.send_to(&packet[..len + HEADER_LEN], (&endpoint[..], port)));
+ try!(udp.send_to(&packet[..len + HEADER_LEN], destination));
 
  sequence = sequence.wrapping_add(1);
  timestamp = timestamp.wrapping_add(960);