Fix an issue in barcode filtering

        // generate the corrected key

        uint32_t corrected_barcode_key = barcode_key_to_change | (base_to_change << (2 * i));

        barcode_whitelist_lookup_table_iterator = kh_get(k32, barcode_whitelist_lookup_table_, corrected_barcode_key);

        if (barcode_whitelist_lookup_table_iterator != kh_end(barcode_whitelist_lookup_table_)) {

          // find one possible corrected barcode

          double barcode_abundance = kh_value(barcode_whitelist_lookup_table_, barcode_whitelist_lookup_table_iterator) / (double)num_sample_barcodes_;

          int qual_offset = 33;

          int adjusted_qual = barcode_qual[barcode_length - 1 - i] - qual_offset;

          adjusted_qual = adjusted_qual > 40 ? 40 : adjusted_qual;

          adjusted_qual = adjusted_qual < 3 ? 3 : adjusted_qual;

          double score = pow(10.0, ((-adjusted_qual) / 10.0)) * barcode_abundance;

        if (barcode_whitelist_lookup_table_iterator != kh_end(barcode_whitelist_lookup_table_)) {

          // find one possible corrected barcode

          corrected_barcodes_with_quals.emplace_back(BarcodeWithQual{barcode_length - 1 - i, SequenceBatch::Uint8ToChar(base_to_change), barcode_qual[barcode_length - 1 - i], barcode_abundance, score});

        }

      }

        barcode_batch->CorrectBaseAt(barcode_index, corrected_barcodes_with_quals[best_corrected_barcode_index].corrected_base_index, corrected_barcodes_with_quals[best_corrected_barcode_index].correct_base);

        //std::cerr << "score: " << corrected_barcodes_with_quals[best_corrected_barcode_index].score << "\n";

        ++(*num_corrected_barcode);

        return true;

      } else {

        return false;

      }

      //std::cerr << barcode << "\n";

      return true;

    }

  }

}