Bug fix: corrected exception type thrown in case of unexpected connec…

…tion termination

httpcore5/src/main/java/org/apache/hc/core5/http/impl/nio/AbstractHttp1StreamDuplexer.java

@@ -30,7 +30,6 @@
 import java.io.IOException;
 import java.net.SocketAddress;
 import java.nio.ByteBuffer;
-import java.nio.channels.ClosedChannelException;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.SelectionKey;
 import java.nio.channels.WritableByteChannel;
@@ -498,7 +497,7 @@ int streamOutput(final ByteBuffer src) throws IOException {
         ioSession.getLock().lock();
         try {
             if (outgoingMessage == null) {
-                throw new ClosedChannelException();
+                throw new ConnectionClosedException();
             }
             final ContentEncoder contentEncoder = outgoingMessage.getBody();
             final int bytesWritten = contentEncoder.write(src);