Drop Unicode.take_range's optional arg as it's never used

[st0012]

In all usages of Unicode.take_range, the last parameter never receives anything:

lib/reline/line_editor.rb
751:      str = padding_space_with_escape_sequences(Reline::Unicode.take_range(item, 0, str_width), str_width)
810:          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog.column, old_dialog.width)
828:          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog.column, old_dialog.width)
847:          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog.column, width)
866:          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog.column + dialog.width, width)
917:        str = Reline::Unicode.take_range(visual_lines_under_dialog[i], dialog.column, dialog.width)

So we can drop it to make it easier to understand.

(IRB doesn't use this method)

[tompng]

👍