[QT] fix OSX dock icon window reopening
[QT] fix OSX dock icon window reopening

fixes #5878

aspaas/ion,aspaas/ion,MinuteManReserve/mmr-core,MinuteManReserve/mmr-core,MinuteManReserve/mmr-core,aspaas/ion,MinuteManReserve/mmr-core,aspaas/ion,aspaas/ion,aspaas/ion,MinuteManReserve/mmr-core