JSON: made top_layers default coincide with its inherited value when parent is set to default
JSON: made top_layers default coincide with its inherited value when parent is set to default

ynotstartups/Wanhao,bq/Ultimaker-Cura,ad1217/Cura,senttech/Cura,totalretribution/Cura,ad1217/Cura,fieldOfView/Cura,markwal/Cura,markwal/Cura,fieldOfView/Cura,totalretribution/Cura,ynotstartups/Wanhao,hmflash/Cura,hmflash/Cura,Curahelper/Cura,senttech/Cura,bq/Ultimaker-Cura,Curahelper/Cura