fix: bug with conditional

[suhjohn]

Existing isSafe does not get triggered as an or condition if either is undefined due to the following code:

      if (!pornPrediction || !hentaiPrediction) {
        return true;
      }

The PR fixes this logic so that when either pornPrediction < 0.25 or hentaiPrediction < 0.25, isSafe returns false.