message: Make Python tests less nervous about Exception string content
diff: @@ -111,14 +111,14 @@ class ValidationTests(unittest.TestCase):
  client.validation_of_body("123", 150, tempproduct)
  except ValidationError as err:
  self.assertEqual(err.rule, "minimum_ex")
  - self.assertEqual(err.target, "capacity")
  + self.assertIn("capacity", err.target)
  try:
  tempproduct=Product(child=ChildProduct(), capacity=100)
  client.validation_of_body("123", 150, tempproduct)
  except ValidationError as err:
  self.assertEqual(err.rule, "maximum_ex")
  - self.assertEqual(err.target, "capacity")
  + self.assertIn("capacity", err.target)
  try:
  tempproduct=Product(child=ChildProduct(),
  @@ -126,7 +126,7 @@ class ValidationTests(unittest.TestCase):
  client.validation_of_body("123", 150, tempproduct)
  except ValidationError as err:
  self.assertEqual(err.rule, "max_items")
  - self.assertEqual(err.target, "display_names")
  + self.assertIn("display_names", err.target)
  client2 = AutoRestValidationTest(
  "abc123",
  