[Nico syntax] The separation line can not be ignored, even though no meta and description data present

[wonderbeyond]

The source below cant't be built correctly:

Hello world
============

Here is the only content

The relevant code from nico src:

  lines.forEach(function(line) {
    if (recording && line.slice(0, 3) === '---') {
      recording = false;
    } else if (recording) {
      header.push(line);
    } else {
      body.push(line);
    }
  });