Once an accept fails, the server will exit

[quanweiZhou]

Description of problem

The current process will exit the loop if Accept fails once, causing all subsequent links to fail to accept. https://github.com/containerd/ttrpc-rust/blob/v0.5.7/src/sync/server.rs#L426

        let handler = thread::Builder::new()
            .name("listener_loop".into())
            .spawn(move || {
                ...

                loop {
                    ...

                    #[cfg(target_os = "linux")]
                    let fd = match accept4(listener, SockFlag::SOCK_CLOEXEC) {
                        Ok(fd) => fd,
                        Err(e) => {
                            error!("failed to accept error {:?}", e);
                            break;
                        }
                    };

                    ...
            })
            .unwrap();

Expected result

If the Accept error occurs, an error can be output to ensure that the subsequent connect can be accepted normally.

Actual result

If the Accept error is detected, the loop will be exited, causing subsequent requests to fail to be accepted.