In commit f8a9f906
we removed support for crash-upgrade from older versions,
but forgot to remove a check for recovering TRUNCATE TABLE
if MariaDB 10.2.18 or 10.3.9 or earlier were killed and
we are attempting to upgrade to MariaDB 10.5.2 or later.
Already MariaDB 10.4 would refuse to recover such TRUNCATE
operations.