fix typo

app.py

@@ -18,7 +18,7 @@ def main():
     embeddings = HuggingFaceEmbeddings()
     vectordb = Chroma.from_documents(documents=texts,embedding=embeddings)
     # llm = HuggingFaceHub(repo_id="google/flan-t5-small", model_kwargs={"temperature":0,"max_length":200}, huggingfacehub_api_token="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") # type: ignore
-    qa = RetrievalQA.from_chain_type(llm=llm, chain_type="stuff",retriever=vectordb.as_retriever(search_type="mmr", search_kwargs={'fetch_k': 30}), return_source_documents=True)
+    qa = RetrievalQA.from_chain_type(llm=llm(), chain_type="stuff",retriever=vectordb.as_retriever(search_type="mmr", search_kwargs={'fetch_k': 30}), return_source_documents=True)
     query = st.text_input("Ask a question: ")
     qa(inputs=query,return_only_outputs=True)
     result = qa({"query": query})