Remove extra level of indent in subsections which disturbed rendering

With extra indent, the list

  * a
  * b
  * c
  * d

  paragraph

Was rendered as:

<ul>
  <li>a</li>
  <li>b</li>
  <li>c</li>
  <li>
    <p>d</p>
    <p>paragraph</p>
  </il>
</ul>

Instead of:

<ul>
  <li>a</li>
  <li>b</li>
  <li>c</li>
  <li>d</li>
</ul>
<p>paragraph</p>

Worse, all the contents of the section after the last item of the list was
treated as part of the last item of the list, and code blocks were lost.