message: [terminal] Grid: fixes lineAt(nr) with negative values (peek into history).
diff: @@ -638,10 +638,7 @@ inline Line& Grid::lineAt(int _line) noexcept
  {
  assert(crispy::ascending(1 - historyLineCount(), _line, screenSize_.height));
  - if (_line > 0)
  return *next(lines_.begin(), historyLineCount() + _line - 1);
  - else
  - return *next(lines_.begin(), -_line);
  }
  inline Line const& Grid::lineAt(int _line) const noexcept
  