21.7.3 throws an exception if `_sample_factor` is used in a query:
```
CREATE TABLE sessions
(
  `user_id` UInt64
)
ENGINE = MergeTree
ORDER BY user_id 
SAMPLE BY user_id;

insert into sessions values(1);

SELECT
    sum(user_id * _sample_factor) 
FROM sessions
SAMPLE 10000000

DB::Exception: Cannot find column `user_id` in source stream (version 21.8.1.7409 (official build))

SELECT
    sum(user_id) 
FROM sessions
SAMPLE 10000000

sum(user_id)
------------
           1
```
No exception on 21.6.5
{
    return query_info.projection ? query_info.projection->prewhere_info
                                 : query_info.prewhere_info;
}
ReadFromMergeTree::ReadFromMergeTree(
    MergeTreeData::DataPartsVector parts_,
    Names real_column_names_,
    Names virt_column_names_,
    const MergeTreeData & data_,
    const SelectQueryInfo & query_info_,
    StorageMetadataPtr metadata_snapshot_,
    StorageMetadataPtr metadata_snapshot_base_,
    ContextPtr context_,
    size_t max_block_size_,
    size_t num_streams_,
    bool sample_factor_column_queried_,
    std::shared_ptr<PartitionIdToMaxBlock> max_block_numbers_to_read_,
    Poco::Logger * log_)
    : ISourceStep(DataStream{.header = MergeTreeBaseSelectProcessor::transformHeader(
        metadata_snapshot_->getSampleBlockForColumns(real_column_names_, data_.getVirtuals(), data_.getStorageID()),
        getPrewhereInfo(query_info_),