Add explicit opt-out for error swallowing 

Might be better to add an explicit opt-out to swallow internal errors:

```javascript
} catch (e){
    if(this._config.errorSwallow){
       this._logger("Swallowed internal error", e.message)
       // Swallow the error, if this produce an error there is no need to error the function

      return {
        rows: []
     }
   } else {
    throw e
  }
}
```