Bad regex in space delimited parser causes Lute to not start!

[jzohrab]

From Discord, a user (Shijui) configured the space delimited parser like this:

8|Japanese|´='|`='|’='|‘='|...=…|..=‥|.!?。？！|Mr.|Mrs.|Dr.|[A-Z].|Vd.|Vds.|\p{Han}\p{Katakana}\p{Hiragana}|0|1|spacedel

which caused Lute to fail at startup:

  File "/Users/jeff/Documents/Projects/lute-v3/lute/db/data_cleanup.py", line 39, in clean_data
    _set_texts_word_count(session)
  File "/Users/jeff/Documents/Projects/lute-v3/lute/db/data_cleanup.py", line 30, in _set_texts_word_count
    pt = t.book.language.get_parsed_tokens(t.text)
  File "/Users/jeff/Documents/Projects/lute-v3/lute/models/language.py", line 127, in get_parsed_tokens
    return self.parser.get_parsed_tokens(s, self)
  File "/Users/jeff/Documents/Projects/lute-v3/lute/parse/space_delimited_parser.py", line 169, in get_parsed_tokens
    return self._parse_to_tokens(clean_text, language)
  File "/Users/jeff/Documents/Projects/lute-v3/lute/parse/space_delimited_parser.py", line 203, in _parse_to_tokens
    self.parse_para(para, lang, tokens)
  File "/Users/jeff/Documents/Projects/lute-v3/lute/parse/space_delimited_parser.py", line 222, in parse_para
    m = self.preg_match_capture(pattern, text)
..... etc etc
    raise source.error('bad escape %s' % escape, len(escape))
re.error: bad escape \p at position 37

I added a print to the space del parser

$ git diff
diff --git a/lute/parse/space_delimited_parser.py b/lute/parse/space_delimited_parser.py
index 0ef26979..e9bb0ba8 100644
--- a/lute/parse/space_delimited_parser.py
+++ b/lute/parse/space_delimited_parser.py
@@ -34,6 +34,7 @@ class SpaceDelimitedParser(AbstractParser):
     @functools.lru_cache
     def compile_re_pattern(pattern: str, *args, **kwargs) -> re.Pattern:
         """Compile regular expression pattern, cache result for fast re-use."""
+        print(pattern, flush=True)
         return re.compile(pattern, *args, **kwargs)

and got

(Mr\.|Mrs\.|Dr\.|[A-Z]\.|Vd\.|Vds\.|[\p{Han}\p{Katakana}\p{Hiragana}]*)

It didn't like the "\p" -- but that shouldn't break the entire parser, and shouldn't cause Lute to completely die.