Bug 10150 - koha-email-disable error handling

Bug 10150 - koha-email-disable error handling

koha-email-disable now
- Checks the instance exists.
- Checks if email is already disabled.

Regards
To+

Sponsored-by: Universidad Nacional de Córdoba
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Mason James <mtj@kohaaloha.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 31b43ac1fe6830426c80988b93bc15d0fa88e79a)

Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
(cherry picked from commit 72961866afc155327dee10d1a2c4dfbac9075159)

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>