Fix JSON deduping on empty objects or arrays
Fix JSON deduping on empty objects or arrays

Reviewed By: kassens

Differential Revision: D21340719

fbshipit-source-id: 8c643ed53f2d6a4cf8e316cc17c9f0d5ab416201

kassens/relay,yungsters/relay,kassens/relay,atxwebs/relay,cpojer/relay,josephsavona/relay,facebook/relay,voideanvalue/relay,wincent/relay,facebook/relay,wincent/relay,cpojer/relay,yungsters/relay,kassens/relay,facebook/relay,voideanvalue/relay,voideanvalue/relay,josephsavona/relay,josephsavona/relay,wincent/relay,xuorig/relay,kassens/relay,atxwebs/relay,wincent/relay,cpojer/relay,xuorig/relay,facebook/relay,voideanvalue/relay,facebook/relay,facebook/relay,voideanvalue/relay,xuorig/relay,atxwebs/relay,yungsters/relay,kassens/relay,atxwebs/relay,wincent/relay,voideanvalue/relay,xuorig/relay,kassens/relay,xuorig/relay,xuorig/relay,cpojer/relay,wincent/relay