Update helpers.py

helpers.py

@@ -227,7 +227,7 @@ def augment_prompt(query: str, k: int = 10):
     queries = []
     queries.append(query)
     
-    if vectorstore is None:
+    if not vectorstore:
         vectorstore = get_vectorstore()
 
     retriever = vectorstore.as_retriever(search_kwargs={"k": k})