Cannot specify the number of cars if using French train

[glolichen]

sl -[cars] attaches that number of cars to the train. sl -G displays a French TGV train. However sl -[cars] -G displays the TGV train correctly, but only attaches 1 car regardless of the number specified.

[hunabku94]

Cannot use Disco mode with -G too.

[Jiaoding]

I add option -n to show more cars, here is the repository: https://github.com/Jiaoding/SteamLocomotive