Enlarge the term weight difference (#3435)

### What problem does this PR solve?


### Type of change

- [x] Performance Improvement

rag/nlp/query.py

@@ -66,7 +66,7 @@ class FulltextQueryer:
 
     def question(self, txt, tbl="qa", min_match:float=0.6):
         txt = re.sub(
-            r"[ :\r\n\t,，。？?/`!！&\^%%()^]+",
+            r"[ :\r\n\t,，。？?/`!！&\^%%()^\[\]]+",
             " ",
             rag_tokenizer.tradi2simp(rag_tokenizer.strQ2B(txt.lower())),
         ).strip()