WWT: convert array length to boolean (#4150)
WWT: convert array length to boolean (#4150)

Avoids 0 rendering in the browser when array is empty
amyrebecca/Panoptes-Front-End,amyrebecca/Panoptes-Front-End,jelliotartz/Panoptes-Front-End,jelliotartz/Panoptes-Front-End,amyrebecca/Panoptes-Front-End,jelliotartz/Panoptes-Front-End,zooniverse/Panoptes-Front-End