throw if well does not have group target

if it is under GRUP control and OPEN.

opm/simulators/wells/BlackoilWellModelGeneric.cpp

@@ -1968,13 +1968,13 @@ updateNONEProductionGroups(const GasLiftOpt& glo, DeferredLogger& deferred_logge
 
     for (std::size_t w = 0; w < well_state.size(); ++w) {
         const auto& ws = well_state.well(w);
-        if (ws.producer && ws.production_cmode == WellProducerCMode::GRUP) {
+        if (ws.producer && ws.production_cmode == WellProducerCMode::GRUP && ws.status == Well::Status::OPEN) {
             const auto& group_target = ws.group_target;
             if (group_target.has_value()) {
                 targeted_production_groups.insert(group_target->group_name);
             } else {
                 const std::string msg = fmt::format("Well {} is on GRUP control but has no group target assigned.", ws.name);
-                deferred_logger.debug(msg);
+                OPM_DEFLOG_THROW(std::runtime_error, msg, deferred_logger);
             }
         }
     }