QGeoPositionInfoSource::createDefaultSource does not return 0 even system has no default position source and no valid plugins could be found.

QGeoPositionInfoSource::createDefaultSource does not return 0 even system has no default position source and no valid plugins could be found, and because of that main crashes with weather widget if GPS is turned off from positioning settings

Steps to reproduce:

• Add weather widget to screen

• Location update received

• Go to positioning settings (settings - application settings -> positioning )

• disable all positioning methods

• Go to home screen and add another weather widget

• Main crashes with notification "application closed: main"