Bug 20144: [sql_modes] Set default value for Aqbookseller in TestBuilder

Fix for:
Out of range value for column 'tax_rate'

t/db_dependent/Koha/Acquisition/Basket.t

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

t/lib/TestBuilder.pm

@@ -480,6 +480,10 @@ sub _gen_default_values {
         Itemtype => {
             rentalcharge => 0,
         },
+        Aqbookseller => {
+            tax_rate => 0,
+            discount => 0,
+        },
     };
 }