Fix: Error when deleting categories

htdocs/categories/viewcat.php

@@ -72,8 +72,11 @@ if ($user->rights->categorie->supprimer && $_POST["action"] == 'confirm_delete'
  * View
  */
 
+$html = new Form($db);
+
 llxHeader ("","",$langs->trans("Categories"));
 
+
 if ($mesg) print $mesg.'<br>';