安装了imagick扩展之后，运行php脚本，出现如下warning:
PHP Warning: Version warning: Imagick was compiled against Image Magick version 1689 but version 1690 is loaded. Imagick will run but may behave surprisingly in Unknown on line 0
解决方法：
在php的配置文件中，比如:/etc/php.ini, 加上如下配置项即可解决：
imagick.skip_version_check=1