extract_sql has bug

[KWLShadow]

if llm generate response was
LLM Response: intermediate_sql

SELECT XXX

SELECT XXX

when start extract_sql(self, llm_response: str) -> str
the answer will get
SELECT XXX

```sql
SELECT XXX

Will contain in the middle

An error is generated
Error running intermediate SQL: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use……