Log ClassCastException from lambda-defined listener at trace level

Closes gh-22834

spring-context/src/main/java/org/springframework/context/event/SimpleApplicationEventMulticaster.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -177,8 +177,8 @@ public class SimpleApplicationEventMulticaster extends AbstractApplicationEventM
 				// Possibly a lambda-defined listener which we could not resolve the generic event type for
 				// -> let's suppress the exception and just log a debug message.
 				Log logger = LogFactory.getLog(getClass());
-				if (logger.isDebugEnabled()) {
-					logger.debug("Non-matching event type for listener: " + listener, ex);
+				if (logger.isTraceEnabled()) {
+					logger.trace("Non-matching event type for listener: " + listener, ex);
 				}
 			}
 			else {