Fixed an Oracle-specific test case failure

Made a test checking ORM-generated query string case-insensitive.

tests/modeltests/prefetch_related/tests.py

@@ -372,7 +372,9 @@ class MultiTableInheritanceTest(TestCase):
             l = [a.authorwithage for a in Author.objects.prefetch_related('authorwithage')]
 
         # Regression for #18090: the prefetching query must include an IN clause.
-        self.assertIn('authorwithage', connection.queries[-1]['sql'])
+        # Note that on Oracle the table name is upper case in the generated SQL,
+        # thus the .lower() call.
+        self.assertIn('authorwithage', connection.queries[-1]['sql'].lower())
         self.assertIn(' IN ', connection.queries[-1]['sql'])
 
         self.assertEqual(l, [a.authorwithage for a in Author.objects.all()])