Fix: test for JSON in sanity_check.
Fix: test for JSON in sanity_check.

osmium-org/osmium,wffurr/osmium,copyliu/osmium,wffurr/osmium,osmium-org/osmium,copyliu/osmium,copyliu/osmium,osmium-org/osmium,wffurr/osmium,wffurr/osmium,osmium-org/osmium