Add debuging log

src/api_server/impl/SMFSelectionSubscriptionDataRetrievalApiImpl.cpp

@@ -77,6 +77,8 @@ void SMFSelectionSubscriptionDataRetrievalApiImpl::get_smf_sel_data(
   m_udm_app->handle_smf_selection_subscription_data_retrieval(
       supi, response_data, http_code, supported_features_str, plmn_id);
 
+  Logger::udm_server().debug("HTTP response code %d", http_code);
+
   code = static_cast<Pistache::Http::Code>(http_code);
   // Set content type
   if ((code == Pistache::Http::Code::Created) or