#1869 and ensure naming

Signed-off-by: a <a>

src/main/resources/templates/fragments/common.html

@@ -148,6 +148,7 @@
                   const multipleInputsForSingleRequest = /*[[${multipleInputsForSingleRequest}]]*/ false;
                   const disableMultipleFiles = /*[[${disableMultipleFiles}]]*/ false;
                   const remoteCall = /*[[${remoteCall}]]*/ true;
+                  const sessionExpired = /*[[#{session.expired}]]*/ '';
                 </script>
                 <script th:src="@{'/js/downloader.js'}"></script>