message: Fix one more occurrence of a move-only conversion to a StatusOr.
diff: @@ -68,7 +68,7 @@ util::StatusOr<std::unique_ptr<JwtMacInternal>> CreateJwtMac() {
  }
  std::unique_ptr<JwtMacInternal> jwt_mac = absl::make_unique<JwtMacImpl>(
  *std::move(mac), "HS256", /*kid=*/absl::nullopt);
  - return jwt_mac;
  + return std::move(jwt_mac);
  }
  TEST(JwtMacImplTest, CreateAndValidateToken) {
  