message: Use correct index in ValiditySegment::FetchRow
diff: @@ -38,10 +38,11 @@ void ValiditySegment::InitializeScan(ColumnScanState &state) {
  }
  void ValiditySegment::FetchRow(ColumnFetchState &state, row_t row_id, Vector &result, idx_t result_idx) {
  + D_ASSERT(row_id >= 0 && row_id < row_t(this->tuple_count));
  auto &buffer_manager = BufferManager::GetBufferManager(db);
  auto handle = buffer_manager.Pin(block);
  ValidityMask mask((validity_t *) handle->node->buffer);
  - if (!mask.RowIsValidUnsafe(row_id - this->row_start)) {
  + if (!mask.RowIsValidUnsafe(row_id)) {
  FlatVector::SetNull(result, result_idx, true);
  }
  }
  