Fixes LeanData.cs hard-coded Market.USA
Fixes LeanData.cs hard-coded Market.USA

It prevents support for new markets.

redmeros/Lean,redmeros/Lean,Jay-Jay-D/LeanSTP,jameschch/Lean,kaffeebrauer/Lean,AlexCatarino/Lean,StefanoRaggi/Lean,QuantConnect/Lean,AnshulYADAV007/Lean,AnshulYADAV007/Lean,Jay-Jay-D/LeanSTP,JKarathiya/Lean,JKarathiya/Lean,StefanoRaggi/Lean,AnshulYADAV007/Lean,AlexCatarino/Lean,jameschch/Lean,StefanoRaggi/Lean,redmeros/Lean,AnshulYADAV007/Lean,AnshulYADAV007/Lean,jameschch/Lean,redmeros/Lean,StefanoRaggi/Lean,Jay-Jay-D/LeanSTP,AlexCatarino/Lean,QuantConnect/Lean,QuantConnect/Lean,Jay-Jay-D/LeanSTP,AlexCatarino/Lean,kaffeebrauer/Lean,kaffeebrauer/Lean,kaffeebrauer/Lean,JKarathiya/Lean,JKarathiya/Lean,jameschch/Lean,Jay-Jay-D/LeanSTP,jameschch/Lean,kaffeebrauer/Lean,StefanoRaggi/Lean,QuantConnect/Lean