Remove unnecessary check in ConvertingEncoderDecoderSupport

Author: chenqimiao

spring-websocket/src/main/java/org/springframework/web/socket/adapter/standard/ConvertingEncoderDecoderSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -85,7 +85,7 @@ public abstract class ConvertingEncoderDecoderSupport<T, M> {
 	 */
 	public void init(EndpointConfig config) {
 		ApplicationContext applicationContext = getApplicationContext();
-		if (applicationContext != null && applicationContext instanceof ConfigurableApplicationContext) {
+		if (applicationContext instanceof ConfigurableApplicationContext) {
 			ConfigurableListableBeanFactory beanFactory =
 					((ConfigurableApplicationContext) applicationContext).getBeanFactory();
 			beanFactory.autowireBean(this);