Release buffer when ChunkedInput is suspended, close AsyncHttpClient#1029

Author: slandelle

client/src/main/java/org/asynchttpclient/netty/request/body/BodyChunkedInput.java

@@ -55,6 +55,7 @@ public ByteBuf readChunk(ChannelHandlerContext ctx) throws Exception {
             return buffer;
         case SUSPEND:
             // this will suspend the stream in ChunkedWriteHandler
+            buffer.release();
             return null;
         case CONTINUE:
             return buffer;