修改前
修改之前， 日志打印为：
access_log logs/access.log main;
其中，mian为前一行自定义的log_format;
修改后
if ($time_iso8601 ~ "^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})") {
set $year $1;
set $month $2;
set $day $3;
set $hour $4;
set $minutes $5;
set $seconds $6;
}
access_log logs/$year-$month-$day-access.log main;
