Header first column deleted when no rows

Problem/Motivation

If there is no paragraph/row, the first column of the header is not shown.

Steps to reproduce

Use a paragraph with "paragraph table form display" create a new content : the first column is missing until you add a row.

Proposed resolution

The paragraph module removes this column because if there no rows to display there should be no "tabledrag" column (index 1), see: paragraphs_preprocess_field_multiple_value_form()

Remaining tasks

_paragraphs_table_header() should add another column (index1) when there is no row.