**Describe the issue**
```
SELECT xyz

Query id: 0c7d8017-4686-404c-9991-388d9a693e5f


0 rows in set. Elapsed: 0.003 sec. 

Received exception from server (version 21.2.1):
Code: 47. DB::Exception: Received from localhost:9000. DB::Exception: Missing columns: 'xyz' while processing query: 'SELECT xyz', required columns: 'xyz', maybe you meant: .
```

The fragment `maybe you meant: .` should not be present.
if (storage)
    {
        const auto storage_virtuals = storage->getVirtuals();
        for (auto it = unknown_required_source_columns.begin(); it != unknown_required_source_columns.end();)
        {
            auto column = storage_virtuals.tryGetByName(*it);
            if (column)
            {
                source_columns.push_back(*column);
                unknown_required_source_columns.erase(it++);
            }
            else
                ++it;
        }
    }
    if (!unknown_required_source_columns.empty())
    {
        WriteBufferFromOwnString ss;
        ss << "Missing columns:";
        for (const auto & name : unknown_required_source_columns)
            ss << " '" << name << "'";
        ss << " while processing query: '" << queryToString(query) << "'";
        ss << ", required columns:";
        for (const auto & name : columns_context.requiredColumns())
            ss << " '" << name << "'";
        if (storage)
        {
            ss << ", maybe you meant: ";
            for (const auto & name : columns_context.requiredColumns())
            {