TFCSONNXHandler: fixed clang warning

Braces around scalar initializer

Simulation/ISF/ISF_FastCaloSim/ISF_FastCaloSimEvent/src/TFCSONNXHandler.cxx

@@ -324,7 +324,7 @@ void TFCSONNXHandler::writeBytesToTTree(TTree &tree,
 void TFCSONNXHandler::readSerializedSession() {
   ATH_MSG_DEBUG("Transforming bytes to session.");
   Ort::Env env(ORT_LOGGING_LEVEL_WARNING, "test");
-  Ort::SessionOptions opts({nullptr});
+  Ort::SessionOptions opts{nullptr};
   m_session =
       std::make_unique<Ort::Session>(env, m_bytes.data(), m_bytes.size(), opts);
   ATH_MSG_DEBUG("Transformed bytes to session.");