Bug 18512 - GetAuthorisedValues.GetByCode Template plguin should return code (not...

Bug 18512 - GetAuthorisedValues.GetByCode Template plguin should return code (not empty string) if value not found

To test:
1 - Create or edit a borrower with info in Sort1 and Sort2 field, not
mapped to authorized values
2 - Note this info does not display on moremember.tt
3 - Apply patch
4 - Note value is passed through

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>