Bug 28236: Allow access to json files from apache config

Bug 28236: Allow access to json files from apache config

This patch grants json files from koha-tmpl. Otherwise systempreferences won't be able to fetch them.

TEST PLAN:

1) Try to set systempreference BorrowerUnwantedField.
2) The modal is empty.
3) Modify Apache configurations like in this patch.
4) Try again set the systempreference.
5) The modal should show list of parameters.

Sponsored-by: Koha-Suomi Oy
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
JD Amended patch: replace tab characters and reword commit title

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>