revert model

app.py

@@ -24,7 +24,7 @@ def pdf_changes(pdf_doc):
     retriever = db.as_retriever()
     global qa 
     qa = ConversationalRetrievalChain.from_llm(
-        llm=OpenAI(model="text-davinci-003", temperature=0.5),  
+        llm=OpenAI(temperature=0.5),  
         retriever=retriever, 
         return_source_documents=False)
     return "Ready"