ASCOM camera: fix crash attempting to set camera cooler after camera is disconnected
ASCOM camera: fix crash attempting to set camera cooler after camera is disconnected

OpenPHDGuiding/phd2,OpenPHDGuiding/phd2,OpenPHDGuiding/phd2,OpenPHDGuiding/phd2,OpenPHDGuiding/phd2,OpenPHDGuiding/phd2