Lower logging level of audit events

Closes gh-3107

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/audit/listener/AuditListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2015 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.
@@ -26,6 +26,7 @@ import org.springframework.context.ApplicationListener;
  * them in a {@link AuditEventRepository}.
  *
  * @author Dave Syer
+ * @author Stephane Nicoll
  */
 public class AuditListener implements ApplicationListener<AuditApplicationEvent> {
 
@@ -39,7 +40,9 @@ public class AuditListener implements ApplicationListener<AuditApplicationEvent>
 
 	@Override
 	public void onApplicationEvent(AuditApplicationEvent event) {
-		logger.info(event.getAuditEvent());
+		if (logger.isDebugEnabled()) {
+			logger.debug(event.getAuditEvent());
+		}
 		this.auditEventRepository.add(event.getAuditEvent());
 	}