Fix not re-subscribing to topics on reconnect

internal/mqtt/mqtt.go

@@ -22,6 +22,7 @@ func NewClient(logger *zap.Logger, config *config.Config, csvHelper *csv.Helper)
 		switch n := notification.(type) {
 		case mqtt.ConnectionNotificationConnected:
 			logger.Info("Connected to MQTT broker")
+			StartListening(logger, config, client)
 		case mqtt.ConnectionNotificationConnecting:
 			logger.Info("connecting", zap.Bool("isReconnect", n.IsReconnect), zap.Int("attempt", n.Attempt))
 		case mqtt.ConnectionNotificationFailed: