Fixed test failures with Oracle when pytz isn't installed.

    from django.core.exceptions import ImproperlyConfigured

    raise ImproperlyConfigured("Error loading cx_Oracle module: %s" % e)

try:

    import pytz

except ImportError:

    pytz = None

from django.db import utils

from django.db.backends import *

from django.db.backends.oracle.client import DatabaseClient

    supports_subqueries_in_group_by = False

    supports_transactions = True

    supports_timezones = False

    has_zoneinfo_database = pytz is not None

    supports_bitwise_or = False

    can_defer_constraint_checks = True

    ignores_nulls_in_unique_constraints = False