Revert "MDEV-14681 Bogus ER_UNSUPPORTED_EXTENSION", fix differently
Revert "MDEV-14681 Bogus ER_UNSUPPORTED_EXTENSION", fix differently

This reverts commit b13f1cc59adb097b8c449730da2c1962493847f4

Don't scan the list of added columns for every row
in copy_data_between tables.

natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2