Fixed path to analytics-events in boot file

refs 0b79abf5b2

- in the referenced commit, we refactored the boot code to simplify it
- one of the required files was not updated with the change, so the path
  was wrong
- this wouldn't have been easily visible from local testing because it's
  based upon a config flag that isn't on by default
- this commit updates the path to the file

core/boot.js

@@ -94,7 +94,7 @@ const initServices = async ({config}) => {
 
     // Initialise analytics events
     if (config.get('segment:key')) {
-        require('./analytics-events').init();
+        require('./server/analytics-events').init();
     }
 
     debug('End: initialiseServices');