This patch fixes useless warnings being printed by `viewlog.pl` I
noticed while testing this new feature.
To test:
1. Test the feature introduced by this patchset
2. Make sure you are running:
$ ktd --shell
k$ tail -f /var/log/koha/kohadev/*.log
=> FAIL: You see things like:
```
[2025/09/26 18:37:39] [WARN] Use of uninitialized value in substr at /kohadevbox/koha/tools/viewlog.pl line 156.
[2025/09/26 18:37:39] [WARN] Use of uninitialized value in substr at /kohadevbox/koha/tools/viewlog.pl line 156.
[2025/09/26 18:37:39] [WARN] Use of uninitialized value in substr at /kohadevbox/koha/tools/viewlog.pl line 156.
[2025/09/26 18:37:39] [WARN] Use of uninitialized value in substr at /kohadevbox/koha/tools/viewlog.pl line 156.
[2025/09/26 18:37:39] [WARN] Use of uninitialized value in substr at /kohadevbox/koha/tools/viewlog.pl line 156.
[2025/09/26 18:43:44] [WARN] Use of uninitialized value in substr at /kohadevbox/koha/tools/viewlog.pl line 156.
[2025/09/26 18:43:44] [WARN] Use of uninitialized value in substr at /kohadevbox/koha/tools/viewlog.pl line 156.
```
3. Refresh the viewlog page
=> FAIL: They are consistent
4. Apply this patch
5. Repeat 3
=> SUCCESS: No more warnings!
6. Sign off :-D
Signed-off-by: Tomás Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Lisette Scheer <lisette@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@openfifth.co.uk>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
95ce864450