Fix crash due to calling GameView::gameOver inside GameView::startNewGame

It happens if you are running computer players only
This is a bit of "a hack", the problem lies in that there's some eventloops
inside the inner parts of the code, and that can make that the game ends
before GameView::startNewGame actually reaches its end

The proper solution would be exotic and this patch seems "simple enough"
so let's go the "easy way"

Comes from SVN review 7013