Use Netty's pooled memory allocator

Instead of the adaptative one, which is the default in 4.2.
The pooled allocator was the default in 4.1.

Author: acogoluegnes

src/main/qpid/org/apache/qpid/protonj2/client/transport/netty4/TcpTransport.java

@@ -23,6 +23,7 @@
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import io.netty.buffer.PooledByteBufAllocator;
 import org.apache.qpid.protonj2.buffer.ProtonBuffer;
 import org.apache.qpid.protonj2.buffer.ProtonBufferAllocator;
 import org.apache.qpid.protonj2.buffer.ProtonBufferComponent;
@@ -412,6 +413,7 @@ private void configureNetty(Bootstrap bootstrap, TransportOptions options) {
         bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, options.connectTimeout());
         bootstrap.option(ChannelOption.SO_KEEPALIVE, options.tcpKeepAlive());
         bootstrap.option(ChannelOption.SO_LINGER, options.soLinger());
+        bootstrap.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
 
         if (options.sendBufferSize() != -1) {
             bootstrap.option(ChannelOption.SO_SNDBUF, options.sendBufferSize());