fix when there is no redirection url defined

web/src/main/webapp/login.xhtml

@@ -52,7 +52,10 @@
         }
 
         function init() {
-            $("#from")[0].value = minerva.GuiConnector.getParams["from"];
+            var fromPage = minerva.GuiConnector.getParams["from"];
+            if (fromPage !== undefined && fromPage !== null && fromPage !== "") {
+                $("#from")[0].value = minerva.GuiConnector.getParams["from"];
+            }
             $('#login').click(function (e) {
                 if (!loggedIn) {
                     e.preventDefault();