Polish

See gh-30357

Author: izeye

spring-websocket/src/main/java/org/springframework/web/socket/messaging/StompSubProtocolHandler.java

@@ -466,7 +466,7 @@ else if (StompCommand.CONNECTED.equals(command)) {
 
 		if (StompCommand.ERROR.equals(command) && getErrorHandler() != null) {
 			Message<byte[]> errorMessage = getErrorHandler().handleErrorMessageToClient(
-					MessageBuilder.createMessage((byte[]) message.getPayload(), accessor.getMessageHeaders()));
+					MessageBuilder.createMessage(payload, accessor.getMessageHeaders()));
 			if (errorMessage != null) {
 				accessor = MessageHeaderAccessor.getAccessor(errorMessage, StompHeaderAccessor.class);
 				Assert.state(accessor != null, "No StompHeaderAccessor");