Fix: skip notes that fail to fetch instead of crashing

[lee90fly]

Problem

When get_note_by_id_from_html returns empty for a single note (e.g. due to rate limit or anti-bot), the original code raises an Exception which crashes the entire crawler run.

Solution

Replace the raise Exception(...) with a utils.logger.warning(...) and return None, so the crawler skips that note and continues with the rest.

Test

Tested locally on xhs platform with 13 keywords. Previously crashed after 1-5 notes, now runs through full keyword list successfully.