Bug 21613: Turn strict SQL modes on for tests

Bug 21613: Turn strict SQL modes on for tests

This patch will turn the strict SQL modes on When tests are ran with prove.

Test plan:
- Apply the first patch
- prove t/db_dependent/Koha/Database.t
=> Will pass if you have <strict_sql_modes>1</strict_sql_modes> in your
koha-conf.xml
=> Will fail otherwise
- Apply the second patch
- prove t/db_dependent/Koha/Database.t
=> Will pass whatever the value of strict_sql_modes in your
koha-conf.xml

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>