The parameter innodb_log_checksums that was introduced in MariaDB 10.2.2
via mysql/mysql-server@af0acedd885eb7103e319f79d25fda7386ef1506
does not make much sense. The original motivation of introducing this
parameter (initially called innodb_log_checksum_algorithm in
mysql/mysql-server@22ba38218e1d76c24f69b5a5595ad3bf5933acb0)
was that the InnoDB redo log used the slow and insecure innodb algorithm.
With hardware or SIMD accelerated CRC-32C, there should be no reason to
allow checksums to be disabled on the redo log.

The parameter innodb_encrypt_log already implies innodb_log_checksums=ON.

Let us deprecate the parameter innodb_log_checksums and always compute
redo log checksums, even if innodb_log_checksums=OFF is specified.

An upgrade from MariaDB 10.2.2 or later will only be possible after
using the default value innodb_log_checksums=ON. If the non-default
value innodb_log_checksums=OFF was in effect when the server was shut down,
a log block checksum mismatch will be reported and the upgraded server
will fail to start up.