parallal update evse station config

EVCB_OCPP.WSServer/Service/StationConfigService.cs

@@ -101,15 +101,17 @@ public class StationConfigService
         stationConfigRecord = dbStationEvseConfig;
 
         Dictionary<string, WsClientData>.ValueCollection connectedEvses = portalServer.GetClientDic().Values;
+        List<Task> updateTasks = new List<Task>();
         foreach (WsClientData evse in connectedEvses)
         {
             int? sessionStationId = GetSessionStation(evse);
             if (sessionStationId is not null &&
                 modifiedStations.Contains(sessionStationId.Value))
             {
-                await UpdateEvseConfig(evse.ChargeBoxId, sessionStationId.Value);
+                var tmp = UpdateEvseConfig(evse.ChargeBoxId, sessionStationId.Value);
             }
         }
+        await Task.WhenAll(updateTasks);
     }
 
     private async Task UpdateStationChangedEvses()