fix: fixed the issue that the llm field in the KeywordExtract form had no default value (#1510)

### What problem does this PR solve?
fix: fixed the issue that the llm field in the KeywordExtract form had
no default value

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/flow/hooks.ts

@@ -82,7 +82,10 @@ export const useInitializeOperatorParams = () => {
         llm_id: llmId,
       },
       [Operator.Message]: initialMessageValues,
-      [Operator.KeywordExtract]: initialKeywordExtractValues,
+      [Operator.KeywordExtract]: {
+        ...initialKeywordExtractValues,
+        llm_id: llmId,
+      },
       [Operator.DuckDuckGo]: initialDuckValues,
       [Operator.Baidu]: initialBaiduValues,
     };