Qmlviewer: qmlviewer will crash after closing the application "flickr demo"

Pre-condition:
wifi is connected and works well.

Reproduction Steps:
1. execute flickr.qml using qmlviewer
2. wait pictures to be shown in grid view
3. click "X" button in the left-top position to close the application

Expected Result: the application is closed without any error message.
Actual Result: the application is closed, but error message "Application Closed: qmlviewer" prompt.

Detail information please refer to: https://qtrequirements.troll.no/browse/QT-4636