Also forward the bytesWritten(qint64) signal
Also forward the bytesWritten(qint64) signal

The signal bytesWritten(qint64) is part of the public API
and should be emitted. Seems it was just forgotten.

Change-Id: I85a56c22581c6bd3ecc504add34aeeabc76f4d2a
Reviewed-by: Kurt Pattyn <da83d6ada5df79ff647b4271d0d788c6f1bafca2@gmail.com>

pixty/qtwebsockets,pixty/qtwebsockets