Try to remove errors from postgres/mysql

They are failing trying to close a db handle that is not needed for
this test. So open the db like all of the rest of the tests.

It's ok that it's not used.

Author: rouilj

test/db_test_base.py

@@ -2985,6 +2985,8 @@ def init_ab(self):
     def test_splitDesignator(self):
         from roundup.hyperdb import splitDesignator, DesignatorError
 
+        self.open_database() # allow setup/shutdown to work to postgres/mysql
+
         valid_test_cases = [('zip2py44', ('zip2py', '44')),
                               ('zippy2', ('zippy', '2')),
                               ('a9', ('a', '9')),