**Describe the unexpected behaviour**
```
milovidov-desktop :) SET output_format_pretty_row_numbers = 1

SET output_format_pretty_row_numbers = 1

Query id: bb15ca27-5a3c-48ac-814a-a3cfea42deda

Ok.

0 rows in set. Elapsed: 0.000 sec. 

milovidov-desktop :) SELECT 1 UNION ALL SELECT 2

SELECT 1
UNION ALL
SELECT 2

Query id: d940f566-7188-4d17-83d6-8421975791a9

   ┌─1─┐
1. │ 2 │
   └───┘
   ┌─1─┐
1. │ 1 │
   └───┘

2 rows in set. Elapsed: 0.001 sec.
```
{
    auto num_rows = chunk.getNumRows();
    auto num_columns = chunk.getNumColumns();
    const auto & columns = chunk.getColumns();
    const auto & header = getPort(port_kind).getHeader();
    WidthsPerColumn widths;
    Widths max_widths;
    Widths name_widths;
    calculateWidths(header, chunk, widths, max_widths, name_widths);
    const GridSymbols & grid_symbols = format_settings.pretty.charset == FormatSettings::Pretty::Charset::UTF8 ?
                                       utf8_grid_symbols :
                                       ascii_grid_symbols;
    /// Create separators
    WriteBp_separator;
    WriteBufferFromOwnString middle_names_separator;
    WriteBufferFromOwnString middle_values_separator;
    WriteBufferFromOwnString bottom_separator;
    top_separator           << grid_old_left_top_corner;
    middle_names_separator  << grid_old_left_separator;