Bug 15073: Move FeeOnChangePatronCategory

Bug 15073: Move FeeOnChangePatronCategory

This patch moves the FeeOnChangePatronCategory system
preference so that it's in a more logical place. Also
a few typos were fixed.

To test:

* Go to System Preferences
* Go to Patrons
* Find FeeOnChangePatronCategory and confirm

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Confirmed. No errors.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>