Start the registration task independent of wether it's the main context

spring-boot-admin-client/src/main/java/de/codecentric/boot/admin/client/registration/RegistrationApplicationListener.java

 /*
- * Copyright 2014-2017 the original author or authors.
+ * Copyright 2014-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,7 +49,7 @@ public class RegistrationApplicationListener {
     @EventListener
     @Order(Ordered.LOWEST_PRECEDENCE)
     public void onApplicationReady(ApplicationReadyEvent event) {
-        if (event.getApplicationContext().getParent() == null && autoRegister) {
+        if (autoRegister) {
             startRegisterTask();
         }
     }