[data] removes extra ul element

site/read/en.html

@@ -12,7 +12,7 @@
 <div
   id="toctitle"
   style="font-family:Montserrat, 'Open Sans', 'DejaVu Sans', sans-serif;"><a href="https://methal.pages.unistra.fr/en.html">Navigation</a></div>
-<ul class="sectlevel1"><ul class="sectlevel1">
+<ul class="sectlevel1">
 <li><a href="../en.html#_objectives">Objectives</a></li>
 <li><a href="../en.html#_challenges">Challenges</a></li>
 <li><a href="../en.html#_outputs">Outputs</a></li>