Use (?i) to match case-insensitively
eg: rewrite (?i)/(Cheap-[^\/]+\.html)(.*)$ /filter.php?route=$1 last;
参考：http://stackoverflow.com/questions/21577841/nginx-case-insensitive-url-redirection
Nginx - rewrite 不区分大小写进行匹配
原文：http://www.cnblogs.com/archoncap/p/4877125.html
