Wrong configuration parameter for the decoder in the training script of the NN-based intra prediction (wrong configuration from MR !43).

At this line https://vcgit.hhi.fraunhofer.de/jvet-ahg-nnvc/VVCSoftware_VTM/-/blob/VTM-11.0_nnvc/training/training_intra_prediction/generating_data_intra.py#L358, "--NnIntraPred" cannot be interpreted by the decoder. This line was added in MR !43 (merged).