Improve logging in spring-messaging

Before this change the amount of logging was too little or too much
with TRACE turned on. This change separates useful debugging
information and logs it under DEBUG and leaves more detailed
information to be logged under TRACE.

spring-websocket/src/main/java/org/springframework/web/socket/support/LoggingWebSocketHandlerDecorator.java

@@ -49,8 +49,8 @@ public class LoggingWebSocketHandlerDecorator extends WebSocketHandlerDecorator
 
 	@Override
 	public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {
-		if (logger.isDebugEnabled()) {
-			logger.debug(message + ", " + session);
+		if (logger.isTraceEnabled()) {
+			logger.trace(message + ", " + session);
 		}
 		super.handleMessage(session, message);
 	}