Allow spaces in XML replies.

[pithos] / pithos / api / templates / containers.xml

<?xml version="1.0" encoding="UTF-8"?>

<account name="{{ account }}">
  {% for container in containers %}
  <container>
  {% for key, value in container.items %}
    <{{ key }}>{{ value }}</{{ key }}>
  {% endfor %}
  </container>
  {% endfor %}
</account>