user_picture prints empty article elements in node/comments

Problem/Motivation

As per the title, an empty article element is output when there is no user picture but user pictures are enabled.

Proposed resolution

Move the control in user.htm.twig, i.e.:

 {% if content %}
  <article{{ attributes }}>
    {{- content -}}
  </article>
{% endif %}

Remaining tasks

Write a patch, or discuss if there is a larger issue at play here.

User interface changes

None.

API changes

None.