[client] Do not reconnect to mgm server in case of handler error (#3856)

* Do not reconnect to mgm server in case of handler error
Set to nil the flow grpc client to nil

* Better error handling

Author: pappz

client/internal/netflow/manager.go

@@ -123,8 +123,14 @@ func (m *Manager) disableFlow() error {
 
 	m.logger.Close()
 
-	if m.receiverClient != nil {
-		return m.receiverClient.Close()
+	if m.receiverClient == nil {
+		return nil
+	}
+
+	err := m.receiverClient.Close()
+	m.receiverClient = nil
+	if err != nil {
+		return fmt.Errorf("close: %w", err)
 	}
 
 	return nil

management/client/grpc.go

@@ -260,8 +260,6 @@ func (c *GrpcClient) receiveEvents(stream proto.ManagementService_SyncClient, se
 
 		if err := msgHandler(decryptedResp); err != nil {
 			log.Errorf("failed handling an update message received from Management Service: %v", err.Error())
-			// hide any grpc error code that is not relevant for management
-			return fmt.Errorf("msg handler error: %v", err.Error())
 		}
 	}
 }