add data-secure to form, closes #2502

Closes #2502

Merge request studip/studip!1959

app/views/admin/semester/edit.php

@@ -4,7 +4,8 @@
  * @var Semester $semester
  */
 ?>
-<form method="post" action="<?= $controller->url_for('admin/semester/edit/' . $semester->id) ?>" data-dialog="size=auto" class="default">
+<form method="post" action="<?= $controller->url_for('admin/semester/edit/' . $semester->id) ?>"
+      data-dialog="size=auto" class="default" data-secure>
     <?= CSRFProtection::tokenTag() ?>
 
     <fieldset>