Use flow-text.

aleksis/apps/untis/templates/untis/untis_import.html

@@ -9,7 +9,7 @@
 
 {% block content %}
 
-  <p class="lead">
+  <p class="flow-text">
     {% blocktrans %}
       Untis provides a function for exporting all data as an XML file.
     {% endblocktrans %}