Try to resend if a send fails

in [`Joinstr::register_input()`](https://github.com/pythcoiner/joinstr/blob/b1e1cc28baab763f08951ed452c382d10ce28b80/src/joinstr/mod.rs#L722) and [`Joinstr::register_output()`](https://github.com/pythcoiner/joinstr/blob/b1e1cc28baab763f08951ed452c382d10ce28b80/src/joinstr/mod.rs#L527) we do not try to resend the message if the send fails, it should be good to do so.