fix: fix a typo

rdagent/scenarios/kaggle/proposal/proposal.py

@@ -94,7 +94,7 @@ def __init__(self, scen: Scenario) -> Tuple[dict, bool]:
         self.initial_performance = 0.0
 
     def generate_RAG_content(self, trace: Trace, hypothesis_and_feedback: str) -> str:
-        if self.scem.if_using_vector_rag:
+        if self.scen.if_using_vector_rag:
             rag_results, _ = self.scen.vector_base.search_experience(hypothesis_and_feedback, topk_k=5)
             return "\n".join([doc.content for doc in rag_results])
         if self.scen.if_using_graph_rag is False or trace.knowledge_base is None: