The MDEV-11738/MDEV-11581 fix was supposed to add the column
ROTATING_OR_FLUSHING to the INFORMATION_SCHEMA table
INNODB_TABLESPACES_ENCRYPTION, but it also added that column to
INNODB_TABLESPACES_SCRUBBING in InnoDB (not XtraDB).

The extra column was never initialized. We will remove it,
because key rotation has nothing to do with the scrubbing of
tablespace data.