Align registration verification request contract

tests/test_registration_verification_adapter.py

@@ -35,6 +35,9 @@ class RegistrationVerificationAdapterTests(unittest.TestCase):
         self.assertEqual("vrq_opaque", receipt.request_id)
         request = opener.call_args.args[0]
         self.assertEqual("Bearer secret", request.headers["Authorization"])
+        payload = json.loads(request.data)
+        self.assertEqual("person@example.test", payload["normalized_email"])
+        self.assertNotIn("email", payload)
         self.assertNotIn(b"return_to", request.data)
 
     @patch("user_engine.adapters.registration_verification.urlopen")