add missing comma in settings file

services/document-updater/config/settings.defaults.js

@@ -171,7 +171,7 @@ module.exports = {
   maxJsonRequestSize:
     parseInt(process.env.MAX_JSON_REQUEST_SIZE, 10) || 8 * 1024 * 1024,
 
-  dispatcherCount: parseInt(process.env.DISPATCHER_COUNT || 10, 10)
+  dispatcherCount: parseInt(process.env.DISPATCHER_COUNT || 10, 10),
 
   mongo: {
     options: {