fixed bug with forced restart of global animations when restarting game

fixed bug with forced restart of global animations when restarting game

This fixes a bug which occured if the game was restarted (by loading a
tape during the game, or by playing again after a game was lost) and
if a custom artwork set was active that used cross-fading for the game
screen. In this case, global animations displayed during the game were
stopped, but not restarted again,