关于 apache：在 PHP5 存在的情况下删除 PHP 7 后 Apache2 不起作用

Apache2 doesn't work after removing PHP 7 while PHP5 exists

我想将我在 Ubuntu 中的 PHP 版本从 7.1 更改为 5.6，我卸载了 PHP7，但现在我无法运行 Apache2。我已经安装了 PHP5.6。
当我尝试重新启动 apache 服务时出现此错误：

Job for apache2.service failed because the control process exited with
error code. See"systemctl status apache2.service" and"journalctl
-xe" for details.

● apache2.service - LSB: Apache2 web server Loaded: loaded
(/etc/init.d/apache2; generated; vendor preset: enabled) Drop-In:
/lib/systemd/system/apache2.service.d
└─apache2-systemd.conf Active: failed (Result: exit-code) since Mon 2017-01-30 10:23:28 CET; 2min 35s ago
Docs: man:systemd-sysv-generator(8) Process: 15026 ExecStop=/etc/init.d/apache2 stop (code=exited, status=0/SUCCESS)
Process: 15052 ExecStart=/etc/init.d/apache2 start (code=exited,
status=1/FAILURE)

*
* The apache2 configtest failed. Output of config test was: apache2: Syntax error on line 216 of /etc/apache2/apache2.conf: Could not open
configuration file /etc/apache2/conf-enabled/phpmyadmin.conf: No such
file or Action 'configtest' failed. The Apache error log may have
more information. apache2.service: Control process exited, code=exited
status=1 Failed to start LSB: Apache2 web server. apache2.service:
Unit entered failed state. apache2.service: Failed with result
'exit-code'.