Dropped this in just now, so the server can populate the flags on store create (via
database::settings) and read them out at startup via dedicated query. When they differ it can issue a startup warning. Just 4 bytes added to the end of the first txs (slab hashmap) table blob (genesis tx association), next to the 1 byte for the Merkle root cache depth.
github.com/libbitcoin/libbitcoin-database/pull/859