Bug 29541: Prevent users from another group to access patron's images

Bug 29541: Prevent users from another group to access patron's images

We should respect group restrictions here.

Test plan:
Create a patron from another group of libraries and don't let them
access info from patrons outside of this group.
Access the following link and confirm that you can see the image only
for patrons from their group
  /cgi-bin/koha/members/patronimage.pl?borrowernumber=XX

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>