Fix the deserialization of CoinEntry
D9169 introduced new methods to make serialization/deserialization
easier to read and write, however the migration of CoinEntry is missing a VARINT() declaration and triggers a database corruption.
ninja all check-all ./src/bitcoind
Should return no database corruption.
Reviewers: #bitcoin_abc, majcosta
Reviewed By: #bitcoin_abc, majcosta
Differential Revision: https://reviews.bitcoinabc.org/D9181