Bug 26997: Fix upgrade process under MySQL 8

Bug 26997: Fix upgrade process under MySQL 8

If you are coming from an old version of Koha, you may face an upgrade
error for the SQL query using 0000-00-00.
The idea was to fix it, but actually the DBMS will raise an error (not
blocking the upgrade process however).

We can hide them to not cause confusion

Errors are like:
DBD::mysql::db do failed: Incorrect date value: '0000-00-00' for column 'suggesteddate' at row 1 [for Statement "UPDATE suggestions SET suggesteddate = '1970-01-01' WHERE suggesteddate = '0000-00-00';"] at /kohadevbox/koha/installer/data/mysql/updatedatabase.pl line 23312.

Test plan:
Checkout an old version of Koha (3.20, not older)
Insert a dump, install Koha
Checkout a recent version of Koha, apply the patch (or use master)
Execute the upgrade process
You should not see the errors

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>