Fix udp discovery not using 74 byte layout

discord/gateway.py

@@ -948,16 +948,16 @@ class DiscordVoiceWebSocket:
         state.voice_port = data['port']
         state.endpoint_ip = data['ip']
 
-        packet = bytearray(70)
+        packet = bytearray(74)
         struct.pack_into('>H', packet, 0, 1)  # 1 = Send
         struct.pack_into('>H', packet, 2, 70)  # 70 = Length
         struct.pack_into('>I', packet, 4, state.ssrc)
         state.socket.sendto(packet, (state.endpoint_ip, state.voice_port))
-        recv = await self.loop.sock_recv(state.socket, 70)
+        recv = await self.loop.sock_recv(state.socket, 74)
         _log.debug('received packet in initial_connection: %s', recv)
 
-        # the ip is ascii starting at the 4th byte and ending at the first null
+        # the ip is ascii starting at the 8th byte and ending at the first null
-        ip_start = 4
+        ip_start = 8
         ip_end = recv.index(0, ip_start)
         state.ip = recv[ip_start:ip_end].decode('ascii')