SOCKS5 Recoder doesn't include UDP traffic metrics

[dengaleev]

The SOCKS5 recorder currently records metrics only for TCP connections, as seen in this code: handler.go, line 139. However, in the case of a UDP association, it does not capture metrics for the UDP connection, which is created here: udp.go, line 65. I thunk the recorder should also include UDP connection statistics. Alternatively, it could record two separate entries: one for TCP connection and one for UDP connection.