QtIFW

If we cancel an download, prevent the failure msgbox.

Make sure to check for cancel in httpError, as the
error gets emited as soon as we call http abort in
cancelDownload(). Later in the chain httpDone would
reset m_canceled and cancelDownload would call httpDone
now with an unset m_canceled, resulting in emmiting an
error.

Change-Id: Ic1e74bef83706dba42ce8d2cb444c08078fa1ed8
Reviewed-by: Niels Weber <niels.2.weber@nokia.com>
Reviewed-by: Tim Jenssen <tim.jenssen@nokia.com>