Wrong port being bound.

[himeno1991]

https://github.com/shadowsocks/shadowsocks-libev/blob/master/src/server.c#L1995

[himeno1991]

Unable to follow the issue template since the template does not provide template questions about describing a typo in code.

I hope it's clear to you that you informed user to bind on port port but then went ahead to bind on server_port.