Fix missing save button on callbacks page

😳

74fb30ce5f (diff-d32e9daf34b835cda7c3b407e14a8feeL31)

app/templates/views/api/callbacks/delivery-status-callback.html

@@ -34,6 +34,7 @@
           hint='At least 10 characters',
           autocomplete='new-password'
         ) }}
+        {{ page_footer('Save') }}
       {% endcall %}
     </div>
   </div>