Create a new template for the File download link

templates/CRM/Dataprocessor/Form/Field/Configuration/FileDownloadLinkOutputHandler.tpl

+{crmScope extensionKey='dataprocessor'}
+  {include file="CRM/Dataprocessor/Form/Field/Configuration/SimpleFieldOutputHandler.tpl"}
+  <div class="crm-section">
+    <div class="label">{$form.return_url.label}</div>
+    <div class="content">{$form.return_url.html}</div>
+    <div class="clear"></div>
+  </div>
+{/crmScope}