The block 202612 PoW workaround previously applied to any block at
height 202612. Restrict it to the object hashes of the known historical
mainnet, testnet, and stagenet block hashing blobs so new chains do not
inherit the fixed PoW hash, which would prevent sync or mining past that
height if their difficulty is higher.
Reported-by: DataHoarder
Co-authored-by: jeffro256 <jeffro256@tutanota.com>
