SNCF requires (young) card number

[gwenaskell]

What I Did

When executing a search for a SNCF connection with a young card, the Trainline server now returns:

{"errors":{"passengers":["La carte Carte Avantage Jeune n’est pas valide : Le numéro de carte doit être rempli(e)"]}}

Seems that SNCF is now requesting the card number as well (as I saw on their website).
I manually added a "number" field to the card stored in the Passenger object, as it is done for TGV MAX card, which solved the problem.