JVET-AE0128 item 2: Update the constraint on when an NNPFC SEI message shall be a repetition of the first NNPFC SEI message in the CLVS
JVET_AE0128 item 2: Update the constraint on when an NNPFC SEI message shall be a repetition of the first NNPFC SEI message in the CLVS