[OLINGO-832] Fixed channel copy

lib/server-core/src/main/java/org/apache/olingo/server/core/ODataHttpHandlerImpl.java

@@ -168,7 +168,7 @@ public class ODataHttpHandlerImpl implements ODataHttpHandler {
       while (input.read(inBuffer) > 0) {
         inBuffer.flip();
         output.write(inBuffer);
-        inBuffer.rewind();
+        inBuffer.clear();
       }
     } catch (IOException e) {
       throw new ODataRuntimeException("Error on reading request content", e);

lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/ChannelSerializerResult.java

@@ -71,6 +71,7 @@ public class ChannelSerializerResult implements SerializerResult {
         if(r <= dest.remaining()) {
           dest.put(buffer);
         } else {
+          r = dest.remaining();
           byte[] buf = new byte[dest.remaining()];
           buffer.get(buf);
           dest.put(buf);