Bug 26341: Database update for bug 21443 is not idempotent and will destroy settings

Bug 26341: Database update for bug 21443 is not idempotent and will destroy settings

If the database update for bug 21443 is run, and the library changes any
of the hourly or daily rental fees following the calendar, a second run
of the database update will overwrite those changes.

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit e708566e729239ed7857c357ee53419c44742ddd)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>