To test:
1) Apply only this patch, skipping the next one (patch 'Use varchar instead of mediumtext')
2) Run ktd up with default DBMS mariadb:10.5: ktd up
3) Confirm the database state is wrong:
DESC categories BlockExpiredPatronOpacActions;
^ This should return type = mediumtext
4) Run updatedatabase, make sure green success message shows
Running the above query again will show type = varchar(128)
5) Run updatedatabase again, notice blue info message notifies its already varchar
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>