Fix dify retrieval issue. (#4473)

### What problem does this PR solve?

#4464
#4469 

### Type of change

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

api/apps/sdk/dify_retrieval.py

@@ -62,7 +62,7 @@ def retrieval(tenant_id):
         for c in ranks["chunks"]:
             c.pop("vector", None)
             records.append({
-                "content": c["content_ltks"],
+                "content": c["content_with_weight"],
                 "score": c["similarity"],
                 "title": c["docnm_kwd"],
                 "metadata": {}