org-ascii-indented-line-width

org-ascii-indented-line-width is a variable defined in `ox-ascii.el'.
Its value is

auto

Documentation:
Additional indentation width for the first line in a paragraph.
If the value is an integer, indent the first line of each
paragraph by this width, unless it is located at the beginning of
a section, in which case indentation is removed from that line.
If it is the symbol `auto' preserve indentation from original
document.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.4 of Emacs.