Fix missing `const`
@@ -266,8 +266,7 @@ const pubsub_engine_s PUBSUB_PROCESS_ENGINE_S = {
};
const pubsub_engine_s *PUBSUB_PROCESS_ENGINE = &PUBSUB_PROCESS_ENGINE_S;
-pubsub_engine_s *PUBSUB_DEFAULT_ENGINE =
- (pubsub_engine_s *)&PUBSUB_CLUSTER_ENGINE_S;
+const pubsub_engine_s *PUBSUB_DEFAULT_ENGINE = &PUBSUB_CLUSTER_ENGINE_S;
/* *****************************************************************************
External Engine Bridge
