Fix LangVersion project setting in Engine project
Fix LangVersion project setting in Engine project

QuantConnect/Lean,AnshulYADAV007/Lean,StefanoRaggi/Lean,Jay-Jay-D/LeanSTP,AlexCatarino/Lean,andrewhart098/Lean,kaffeebrauer/Lean,AlexCatarino/Lean,andrewhart098/Lean,kaffeebrauer/Lean,redmeros/Lean,Jay-Jay-D/LeanSTP,AnshulYADAV007/Lean,Mendelone/forex_trading,jameschch/Lean,AlexCatarino/Lean,redmeros/Lean,young-zhang/Lean,andrewhart098/Lean,kaffeebrauer/Lean,JKarathiya/Lean,young-zhang/Lean,Jay-Jay-D/LeanSTP,JKarathiya/Lean,jameschch/Lean,AnshulYADAV007/Lean,young-zhang/Lean,andrewhart098/Lean,young-zhang/Lean,redmeros/Lean,kaffeebrauer/Lean,redmeros/Lean,AnshulYADAV007/Lean,Mendelone/forex_trading,Jay-Jay-D/LeanSTP,Mendelone/forex_trading,JKarathiya/Lean,StefanoRaggi/Lean,StefanoRaggi/Lean,AnshulYADAV007/Lean,QuantConnect/Lean,StefanoRaggi/Lean,QuantConnect/Lean,QuantConnect/Lean,jameschch/Lean,jameschch/Lean,kaffeebrauer/Lean,StefanoRaggi/Lean,jameschch/Lean,Jay-Jay-D/LeanSTP,AlexCatarino/Lean,JKarathiya/Lean,Mendelone/forex_trading