message: fixed externalCallAvgDuration API for sinusoidal pattern
diff: @@ -240,7 +240,7 @@ func GetUsage(client *SqlClient, query *model.GetUsageParams) (*[]UsageItem, err
  func GetServiceExternalAvgDuration(client *SqlClient, query *model.GetServiceOverviewParams) (*[]ServiceExternalItem, error) {
  sqlQuery := fmt.Sprintf(`SELECT TIME_FLOOR(__time, '%s') as "time", AVG(DurationNano) as "avgDuration" FROM %s WHERE ServiceName='%s' AND Kind='3' AND ExternalHttpUrl != '' AND "__time" >= '%s' AND "__time" <= '%s'
  - GROUP BY TIME_FLOOR(__time, '%s'), ExternalHttpUrl`, query.Period, constants.DruidDatasource, query.ServiceName, query.StartTime, query.EndTime, query.Period)
  + GROUP BY TIME_FLOOR(__time, '%s')`, query.Period, constants.DruidDatasource, query.ServiceName, query.StartTime, query.EndTime, query.Period)
  // zap.S().Debug(sqlQuery)
  