Proxy names specified in 'start' params divided by ',' will be started.
If it is empty or not defined, all proxies will be started.

if login_fail_exit is false, when frpc first login to server failed, it
    will continues relogin to server every 30 seconds.

[new] Optimize for http services.Support virtual host and custom domain binding.
[new] Support max days of keeping log files.
[fix] Fix a bug when reconnecting.