pontoon: make get_devices_async operate on a copy of the devices dict
pontoon: make get_devices_async operate on a copy of the devices dict

unintended/Cohen,sreichholf/python-coherence,unintended/Cohen,opendreambox/python-coherence,ismaelgaudioso/Coherence,furbrain/Coherence,coherence-project/Coherence,sreichholf/python-coherence,opendreambox/python-coherence,ismaelgaudioso/Coherence,furbrain/Coherence,coherence-project/Coherence