Fix KafkaListenerEndpoint#getEndpointDescription

Add a missing left quote in `AbstractKafkaListenerEndpoint.getEndpointDescription()` for `topics`

spring-kafka/src/main/java/org/springframework/kafka/config/AbstractKafkaListenerEndpoint.java

@@ -560,7 +560,7 @@ private void setupMessageListener(MessageListenerContainer container,
 	protected StringBuilder getEndpointDescription() {
 		StringBuilder result = new StringBuilder();
 		return result.append(getClass().getSimpleName()).append("[").append(this.id).
-				append("] topics=").append(this.topics).
+				append("] topics='").append(this.topics).
 				append("' | topicPartitions='").append(this.topicPartitions).
 				append("' | topicPattern='").append(this.topicPattern).append("'");
 	}