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- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 3.1.7
* Operating System version: centos 7.6.1810
* Java version: openjdk-1.8.0_212

### Steps to reproduce this issue

测试环境启动项目后出现,本地复现不出来

### Actual Behavior

```
io.netty.util.ResourceLeakDetector: LEAK: ByteBuf.release() was not called before it's garbage-collected. See http://netty.io/wiki/reference-counted-objects.html for more information.
Recent access records: 
Created at:
	io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:349)
	io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:187)
	io.netty.buffer.UnsafeByteBufUtil.copy(UnsafeByteBufUtil.java:436)
	io.netty.buffer.PooledUnsafeDirectByteBuf.copy(PooledUnsafeDirectByteBuf.java:309)
	io.netty.buffer.AbstractByteBuf.copy(AbstractByteBuf.java:1187)
	org.apache.dubbo.remoting.transport.netty4.NettyBackedChannelBuffer.copy(NettyBackedChannelBuffer.java:169)
	org.apache.dubbo.qos.pu.TelnetDetector.commandDetect(TelnetDetector.java:64)
	org.apache.dubbo.qos.pu.TelnetDetector.detect(TelnetDetector.java:48)
	org.apache.dubbo.qos.pu.QosDetector.detect(QosDetector.java:46)
	org.apache.dubbo.remoting.transport.netty4.NettyPortUnificationServerHandler.decode(NettyPortUnificationServerHandler.java:103)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:502)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:441)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:278)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1408)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:930)
	io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
	io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:682)
	io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:617)
	io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:534)
	io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:496)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:906)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.lang.Thread.run(Thread.java:748)
```

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
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package org.apache.dubbo.remoting.buffer;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
public class DynamicChannelBuffer extends AbstractChannelBuffer {