Suppress duplicate warning message printed when a message reaches at the end of pipeline

transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java

@@ -973,11 +973,13 @@ final class DefaultChannelPipeline implements ChannelPipeline {
                 ByteBufUtil.release(m);
             }
 
+            if (length != 1) {
                 logger.warn(
                         "Discarded {} inbound message(s) that reached at the tail of the pipeline. " +
                         "Please check your pipeline configuration.", length);
             }
         }
+    }
 
     static final class HeadHandler implements ChannelOutboundHandler {