remove errors from json returned to drishti, closes #515
remove errors from json returned to drishti, closes #515

SEL-Columbia/enketo,makinacorpus/enketo,makinacorpus/enketo,HydroLogic/enketo,enketo/enketo-legacy,enketo/enketo-legacy,HydroLogic/enketo,SEL-Columbia/enketo,HydroLogic/enketo,enketo/enketo-legacy,makinacorpus/enketo,makinacorpus/enketo,makinacorpus/enketo,makinacorpus/enketo