Update app.py

fix bug：增加HISTORY_LEN

app.py

@@ -142,13 +142,13 @@ def predict(input,
             embedding_model,
             file_obj,
             VECTOR_SEARCH_TOP_K,
+            HISTORY_LEN,
             temperature,
             top_p,
             use_web,
             history=None):
     if history == None:
         history = []
-    print(file_obj.name)
     vector_store = init_knowledge_vector_store(embedding_model, file_obj.name)
     if use_web == 'True':
         web_content = search_web(query=input)