显示的错误是：
Failed to reload apache2.service: The name org.freedesktop.PolicyKit1 was not provided by
any .service files See system logs and 'systemctl status apache2.service' for details.
我已经运行了以下两个命令，这里分别是返回的日志：
systemctl status apache2.service
journalctl -xe
日志：
systemctl status apache2.service
? apache2.service - LSB: Apache2 web server
Loaded: loaded (/etc/init.d/apache2; bad; vendor preset: enabled)
Drop-In: /lib/systemd/system/apache2.service.d
??apache2-systemd.conf
Active: active (running) since Tue 2017-02-21 18:41:29 IST; 33min ago
Docs: man:systemd-sysv-generator(8)
Process: 14374 ExecStop=/etc/init.d/apache2 stop (code=exited, status=0/SUCCESS
Process: 14396 ExecStart=/etc/init.d/apache2 start (code=exited, status=0/SUCCE
CGroup: /system.slice/apache2.service
??14414 /usr/sbin/apache2 -k …