stdout日志文件不能按大小分割

return [
    'event_loop' => '',
    'stop_timeout' => 2,
    'pid_file' => runtime_path() . '/webman.pid',
    'status_file' => runtime_path() . '/webman.status',
    'stdout_file' => runtime_path() . '/logs/stdout.log',
    'log_file' => runtime_path() . '/logs/workerman.log',
    'size' => 10 * 1024 * 1024
];