Crash for `--latex` and italic `^[[3m`

[sedrubal]

Using this example file: italic.txt

$ cat italic.txt | ansi2html --latex --inline

Crashes with this traceback:

Traceback (most recent call last):
  File "/usr/bin/ansi2html", line 33, in <module>
    sys.exit(load_entry_point('ansi2html==1.6.0', 'console_scripts', 'ansi2html')())
  File "/usr/lib/python3.9/site-packages/ansi2html/converter.py", line 696, in main
    output = conv.convert(
  File "/usr/lib/python3.9/site-packages/ansi2html/converter.py", line 507, in convert
    attrs = self.prepare(ansi, ensure_trailing_newline=ensure_trailing_newline)
  File "/usr/lib/python3.9/site-packages/ansi2html/converter.py", line 485, in prepare
    body, styles = self.apply_regex(ansi)
  File "/usr/lib/python3.9/site-packages/ansi2html/converter.py", line 300, in apply_regex
    parts = self._collapse_cursor(parts)
  File "/usr/lib/python3.9/site-packages/ansi2html/converter.py", line 461, in _collapse_cursor
    for part in parts:
  File "/usr/lib/python3.9/site-packages/ansi2html/converter.py", line 434, in _apply_regex
    yield "\\textcolor[HTML]{%s}{" % style[0]
IndexError: list index out of range