Fix multiple symbol addition in AddToUserDefinedUniverse
Fix multiple symbol addition in AddToUserDefinedUniverse

Fixes #1733

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