fix registration

SurveyFrontend/src/components/RegisterForm/RegisterForm.tsx

@@ -38,10 +38,7 @@ const RegisterForm = () => {
                 const responseData = await registerUser({username, firstName, lastName, email, password});
                 if (responseData && !responseData.error) {
                     console.log('Регистрация успешна');
-                    localStorage.setItem("user", JSON.stringify({
-                        firstName,
-                        lastName
-                    }));
+                    localStorage.setItem("user", JSON.stringify(responseData.user));
                     navigate('/my-surveys');
                 }
                 else if (responseData.status === 409){