Fix flask<1.0.0
Fix flask<1.0.0

Made a mistake originally, meant to flask<1.0.0

timifasubaa/incubator-superset,zhouyao1994/incubator-superset,apache/incubator-superset,timifasubaa/incubator-superset,mistercrunch/panoramix,airbnb/superset,mistercrunch/panoramix,airbnb/caravel,apache/incubator-superset,airbnb/caravel,timifasubaa/incubator-superset,dmigo/incubator-superset,apache/incubator-superset,zhouyao1994/incubator-superset,dmigo/incubator-superset,mistercrunch/panoramix,dmigo/incubator-superset,airbnb/caravel,zhouyao1994/incubator-superset,airbnb/caravel,airbnb/superset,apache/incubator-superset,apache/incubator-superset,zhouyao1994/incubator-superset,airbnb/superset,airbnb/superset,zhouyao1994/incubator-superset,mistercrunch/panoramix,dmigo/incubator-superset,timifasubaa/incubator-superset