[LEVWEB-873] Fix the Start Again button

The Start Again button on the Error page should send users back to the Audit report or the Birth Searchc page based on where they've come from.

middleware/error.js

@@ -1,12 +1,12 @@
 'use strict';
-var config = require('../config');
-var logger = require('../lib/logger');
+const config = require('../config');
+const logger = require('../lib/logger');
 
 module.exports = function errorMiddlewareFactory() {
 
   /* eslint no-unused-vars: 0*/
   return function errorHandler(err, req, res, next) {
-    var content = {};
+    const content = {};
 
     err.template = 'error';
     content.title = content.title || err.error || 'Error';
@@ -21,7 +21,7 @@ module.exports = function errorMiddlewareFactory() {
         error: err,
         content: content,
         showStack: config.env === 'development',
-        startLink: req.path ? req.path.replace(/^\/([^\/]*).*$/, '') : ''
+        startLink: req.path && req.path.startsWith('/audit/user-activity') ? 'audit/user-activity' : ''
       });
     } else {
       // Cannot render