fix single task summary for annotation value=0 (#3472)
fix single task summary for annotation value=0 (#3472)


amyrebecca/Panoptes-Front-End,amyrebecca/Panoptes-Front-End,jelliotartz/Panoptes-Front-End,jelliotartz/Panoptes-Front-End,jelliotartz/Panoptes-Front-End,amyrebecca/Panoptes-Front-End,zooniverse/Panoptes-Front-End