Severity: Notice
Message: Only variable references should be returned by reference
Filename: core/Common.php
Line Number: 257
参考了下面链接
https://www.jb51.net/article/69548.htm
http://blog.itpub.net/15498/viewspace-2134612/
原代码：
return $_config[0] =& $config;
修改后:
$_config[0] =& $config; return $_config[0];
原文：https://www.cnblogs.com/rrison/p/10423821.html