解决Warning: mysql_connect(): Headers and client library minor version mismatch. 警告

php -i|grep Client

查询当前Client 版本，结果如下：

Client API version => 5.6.31
Client API library version => 5.6.31
Client API header version => 5.5.47-MariaDB
Client API version => 5.6.31

yum remove php-mysql  
yum install php-mysqlnd