[hotfix] fixing json endpoint
[hotfix] fixing json endpoint

SingTel-DataCo/incubator-superset,airbnb/superset,zhouyao1994/incubator-superset,mistercrunch/panoramix,alanmcruickshank/superset-dev,woel0007/caravel,apache/incubator-superset,airbnb/superset,robert-digit/superset,airbnb/superset,asdf2014/superset,BRD-CD/superset,FrederichCheng/incubator-superset,tienhv/caravel,mistercrunch/panoramix,wbsljh/caravel-aidp,BRD-CD/superset,dmigo/incubator-superset,ArijanaBrlek/superset,giaosudau/caravel,SingTel-DataCo/incubator-superset,nekia/incubator-superset-dev,francisliyy/caravel-aidp,asdf2014/superset,georgeke/caravel,airbnb/caravel,wbsljh/caravel,airbnb/caravel,georgeke/caravel,woel0007/caravel,dmigo/incubator-superset,zhouyao1994/incubator-superset,jeromecn/caravel_viz_full,georgeke/caravel,francisliyy/caravel-aidp,wbsljh/caravel-aidp,zhouyao1994/incubator-superset,robert-digit/superset,zhouyao1994/incubator-superset,alanmcruickshank/superset-dev,alanmcruickshank/superset-dev,wbsljh/caravel,timifasubaa/incubator-superset,jeromecn/caravel_viz_full,ArijanaBrlek/superset,FrederichCheng/incubator-superset,wbsljh/caravel-aidp,ArijanaBrlek/superset,giaosudau/caravel,nekia/incubator-superset-dev,timifasubaa/incubator-superset,nekia/incubator-superset-dev,ArijanaBrlek/superset,asdf2014/superset,apache/incubator-superset,woel0007/caravel,wbsljh/caravel-aidp,woel0007/caravel,zhouyao1994/incubator-superset,massgov/incubator-superset,BRD-CD/superset,FrederichCheng/incubator-superset,giaosudau/caravel,wbsljh/caravel,airbnb/caravel,massgov/incubator-superset,wbsljh/caravel,francisliyy/caravel-aidp,jeromecn/caravel_viz_full,airbnb/superset,apache/incubator-superset,dmigo/incubator-superset,timifasubaa/incubator-superset,asdf2014/superset,airbnb/caravel,jeromecn/caravel_viz_full,massgov/incubator-superset,apache/incubator-superset,georgeke/caravel,tienhv/caravel,robert-digit/superset,tienhv/caravel,BRD-CD/superset,dmigo/incubator-superset,francisliyy/caravel-aidp,giaosudau/caravel,FrederichCheng/incubator-superset,mistercrunch/panoramix,robert-digit/superset,alanmcruickshank/superset-dev,SingTel-DataCo/incubator-superset,massgov/incubator-superset,tienhv/caravel,apache/incubator-superset,nekia/incubator-superset-dev,mistercrunch/panoramix,SingTel-DataCo/incubator-superset,timifasubaa/incubator-superset