ss-server does not start immediately on boot

[seicowing]

If I add plugin and plugin_opts as value in json, ss-server does not start immediately on boot, simple-obfs is the latest version today.

shadowsocks-libev.service - Shadowsocks-libev Default Server Service
Loaded: loaded (/lib/systemd/system/shadowsocks-libev.service; enabled)
Active: active (running) since Thu 2017-01-19 14:18:42 CST; 6min ago
Docs: man:shadowsocks-libev(8)
Main PID: 580 (ss-server)
CGroup: /system.slice/shadowsocks-libev.service
├─ 580 /usr/bin/ss-server -a root -c /etc/shadowsocks-libev/config.json -u
└─1042 obfs-server

Jan 19 14:18:42 f986bb8d-42b0 ss-server[580]: 2017-01-19 14:18:42 INFO: onetime authentication enabled
Jan 19 14:18:42 f986bb8d-42b0 ss-server[580]: 2017-01-19 14:18:42 INFO: plugin "obfs-server" enabled
Jan 19 14:18:42 f986bb8d-42b0 ss-server[580]: 2017-01-19 14:18:42 INFO: UDP relay enabled
Jan 19 14:18:42 f986bb8d-42b0 ss-server[580]: 2017-01-19 14:18:42 INFO: initializing ciphers... chacha20
Jan 19 14:22:09 localhost ss-server[580]: 2017-01-19 14:22:09 INFO: tcp port reuse enabled
Jan 19 14:22:09 localhost ss-server[580]: 2017-01-19 14:22:09 INFO: tcp server listening at 127.0.0.1:53526
Jan 19 14:22:09 localhost ss-server[580]: 2017-01-19 14:22:09 INFO: udp port reuse enabled
Jan 19 14:22:09 localhost ss-server[580]: 2017-01-19 14:22:09 INFO: udp server listening at 0.0.0.0:3389
Jan 19 14:22:09 localhost ss-server[580]: 2017-01-19 14:22:09 INFO: running from root user
Jan 19 14:22:09 localhost ss-server[580]: 2017-01-19 14:22:09 [simple-obfs] INFO: obfuscating enabled
Jan 19 14:22:09 localhost ss-server[580]: 2017-01-19 14:22:09 [simple-obfs] INFO: tcp port reuse enabled
Jan 19 14:22:09 localhost ss-server[580]: 2017-01-19 14:22:09 [simple-obfs] INFO: listening at 0.0.0.0:3389
Jan 19 14:22:09 localhost ss-server[580]: 2017-01-19 14:22:09 [simple-obfs] INFO: running from root user

[seicowing]

It seems that obfs-server won't start with ss-server at the same time.