remove unused logger field

pkg/bbgo/order_execution.go

@@ -37,11 +37,6 @@ type ExchangeOrderExecutor struct {
 	Notifiability `json:"-"`
 
 	session *ExchangeSession
-	logger  Logger
-}
-
-func (e *ExchangeOrderExecutor) SetLogger(logger Logger) {
-	e.logger = logger
 }
 
 func (e *ExchangeOrderExecutor) notifySubmitOrders(orders ...types.SubmitOrder) {

pkg/bbgo/risk_controls.go

@@ -28,7 +28,6 @@ func (e *RiskControlOrderExecutor) SubmitOrders(ctx context.Context, orders ...t
 			orders, riskErrs = controller.BasicRiskController.ProcessOrders(e.session, orders...)
 			for _, riskErr := range riskErrs {
 				// use logger from ExchangeOrderExecutor
-				e.logger.Warnf(riskErr.Error())
 				logrus.Warnf("RISK ERROR: %s", riskErr.Error())
 			}
 		}

pkg/bbgo/trader.go

@@ -136,7 +136,6 @@ func (trader *Trader) Run(ctx context.Context) error {
 			// copy the environment notification system so that we can route
 			Notifiability: trader.environment.Notifiability,
 			session:       session,
-			logger:        trader.logger,
 		}
 
 		// default to base order executor