Allow neagtive values in Skonto Betrag
In "Gutschriften", there might be a negative amount, hence the BASISBETRAG of Skonto can be neagtive
Although it is kind of exceptional case, it is Norm conform and hence we have to support it.
In "Gutschriften", there might be a negative amount, hence the BASISBETRAG of Skonto can be neagtive
Although it is kind of exceptional case, it is Norm conform and hence we have to support it.