Flush after body frame

Otherwise we fill up the Netty buffer and get stuck.

Author: acogoluegnes

src/main/java/com/rabbitmq/client/impl/NettyFrameHandlerFactory.java

@@ -383,7 +383,6 @@ public void writeFrame(Frame frame) throws IOException {
     private void doWriteFrame(Frame frame) throws IOException {
       ByteBuffer bbPayload = frame.getByteBufferPayload();
       if (bbPayload != null) {
-        // Zero-copy path: write frame header, wrap the ByteBuffer body directly, write frame end
         int payloadSize = bbPayload.remaining();
         ByteBuf header = this.channel.alloc().buffer(7);
         header.writeByte(frame.getType());
@@ -396,8 +395,7 @@ private void doWriteFrame(Frame frame) throws IOException {
         end.writeByte(AMQP.FRAME_END);
 
         ByteBuf composite = Unpooled.wrappedBuffer(header, body, end);
-        // this is for basicPublish, the channel will be flushed later
-        this.channel.write(composite, this.channel.voidPromise());
+        this.channel.writeAndFlush(composite, this.channel.voidPromise());
       } else {
         ByteBuf bb = this.channel.alloc().buffer(frame.size());
         frame.writeToByteBuf(bb);