Remove the size limit of QByteArray information.

The information is explaining implementation details rather than
on how to use it effectively. The size limit of QByteArray may
vary depending on available memory.

Task-number: QTBUG-33037
Change-Id: I361316422ade3624a0c2864d93f87caeb654f4d7
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>