**Describe the bug**
When you set the setting `input_format_with_names_use_header` to `0`, `INSERT` does not actually insert rows.

**How to reproduce**
* Which ClickHouse server version to use: git master `a21fe0b492cbc8628126a3cd493b83e82abf9978`, checked out on 2021-03-31
* Which interface to use: the native command-line client
* Non-default settings, if any: `input_format_with_names_use_header` = `0`
* `CREATE TABLE` statements for all tables involved:
```sql
CREATE TABLE csvtest
(
    `t` String
)
ENGINE = MergeTree
ORDER BY t
```
* Sample data for all these tables
`test.csv`:
```csv
t
testdata1
testdata2
```
* Queries to run that lead to unexpected result:
```
% clickhouse-client --input_format_with_names_use_header 0 --query "INSERT INTO csvtest FORMAT CSVWithNames" < test.csv
```

**Expected behavior**
Two rows `('testdata1'), ('testdata2')` will be inserted to the table `csvtest`.

**Error message and/or stacktrace**
Nothing. It silently discards the input and inserts nothing to the table.

**Additional context**
It works as expected if you set `input_format_with_names_use_header` to `1`.

{
    const bool at_delimiter = !in.eof() && *in.position() == format_settings.csv.delimiter;
    const bool at_last_column_line_end = is_last_file_column
                                         && (in.eof() || *in.position() == '\n' || *in.position() == '\r');
    
    
    if (format_settings.csv.empty_as_default
        && (at_delimiter || at_last_column_line_end))
    {
        
        
        
        
        
        
        column.insertDefault();
        return false;
    }
    else if (format_settings.null_as_default && !type->isNullable())
    {
        
        return SerializationNullable::deserializeTextCSVImpl(column, in, format_settings, serialization);
    }
    else
    {
        
        serialization->deserializeTextCSV(column, in, format_settings);
        return true;
    }