fix progress for redirected HTTP Downloads

 - do not emit the progress in the redirect case for the redirect data

Task-number: QTIFW-267

Change-Id: Id32018a92df3098e45c963b4dcf7924bebdd1354
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>
Reviewed-by: Niels Weber <niels.weber@digia.com>