Increase rendezvous connection info exchange timeouts

[povilasb]

With too short timeouts connections might be prematurily dropped - especially with manual tests.

Also, note that this change indicates duplicate code. It would be really easy to extract it. I simply wonder how to deal with different error types:

                        channel
                        .map_err(TcpRendezvousConnectError::ChannelRead)
                        .next_or_else(|| TcpRendezvousConnectError::ChannelClosed)
                        .with_timeout(
                            Duration::from_secs(RENDEZVOUS_INFO_EXCHANGE_TIMEOUT_SEC),
                            &handle1
                        )
                        .and_then(|opt| opt.ok_or(TcpRendezvousConnectError::ChannelTimedOut))

In case of UDP code is identical except that errors are of UdpRendezvousConnectError type.

[canndrew]

In terms of de-duplication you could move RENDEZVOUS_INFO_EXCHANGE_TIMEOUT_SEC up to a higher module. But I think it's fine the way it is.

[povilasb]

I meant the whole code snippet, not only the constant :)