Utils: Remove assert when hiding progress indicator.
Utils: Remove assert when hiding progress indicator.

Just return silently when trying to hide a progress indicator
that wasn't initialized by showProgressIndicator.

Change-Id: If8c68dbc9de481c8b1cc6b8dd38c9d8e70b00065
Reviewed-by: Eike Ziller <c142da16c73a95a82d35191bcc55b22835617128@theqtcompany.com>

Distrotech/qtcreator,danimo/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,Distrotech/qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,Distrotech/qtcreator,Distrotech/qtcreator,Distrotech/qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,danimo/qt-creator,xianian/qt-creator,Distrotech/qtcreator,danimo/qt-creator,danimo/qt-creator,danimo/qt-creator,martyone/sailfish-qtcreator,danimo/qt-creator,xianian/qt-creator,danimo/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,danimo/qt-creator,xianian/qt-creator,danimo/qt-creator,xianian/qt-creator,xianian/qt-creator,Distrotech/qtcreator