Bug 33645: Make koha-foreach return 0 if it completes successfully

Bug 33645: Make koha-foreach return 0 if it completes successfully

This patch adds an "exit 0" to the end of koha-foreach, so that it
returns a successful exit code if it reaches the bottom of the script
without errors.

Test plan:
0) `koha-foreach echo`
1) `echo $?`
2) Note that the exit status is 1
3) Apply patch
4) `./debian/scripts/koha-foreach echo`
5) `echo $?`
6) Note that the exit status is 0

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