make dataset enable idempotent

src/fsfw/datapoollocal/LocalDataPoolManager.cpp

@@ -718,7 +718,7 @@ ReturnValue_t LocalDataPoolManager::togglePeriodicGeneration(sid_t sid, bool ena
 
   if ((LocalPoolDataSetAttorney::getReportingEnabled(*dataSet) and enable) or
       (not LocalPoolDataSetAttorney::getReportingEnabled(*dataSet) and not enable)) {
-    return REPORTING_STATUS_UNCHANGED;
+    return returnvalue::OK;
   }
 
   LocalPoolDataSetAttorney::setReportingEnabled(*dataSet, enable);