Fix default parameter value for json
Fix default parameter value for json

kotfic/girder,girder/girder,RafaelPalomar/girder,salamb/girder,data-exp-lab/girder,Xarthisius/girder,kotfic/girder,RafaelPalomar/girder,salamb/girder,sutartmelson/girder,salamb/girder,adsorensen/girder,RafaelPalomar/girder,girder/girder,data-exp-lab/girder,adsorensen/girder,jbeezley/girder,Kitware/girder,data-exp-lab/girder,jbeezley/girder,Kitware/girder,adsorensen/girder,Xarthisius/girder,RafaelPalomar/girder,jbeezley/girder,kotfic/girder,Xarthisius/girder,adsorensen/girder,adsorensen/girder,sutartmelson/girder,Xarthisius/girder,girder/girder,jbeezley/girder,salamb/girder,kotfic/girder,manthey/girder,Kitware/girder,sutartmelson/girder,kotfic/girder,sutartmelson/girder,sutartmelson/girder,manthey/girder,manthey/girder,salamb/girder,RafaelPalomar/girder,Kitware/girder,data-exp-lab/girder,data-exp-lab/girder,Xarthisius/girder,manthey/girder,girder/girder