Reject all non-V2 blocks
Reject all non-V2 blocks

All blocks should be V2 which has nHeight. This explicitly rejects any
blocks that are not V2 or do not have nHeight.

neutrinofoundation/neutrino-digital-currency,neutrinofoundation/neutrino-digital-currency,neutrinofoundation/neutrino-digital-currency,neutrinofoundation/neutrino-digital-currency