fix/fix build KB function

utils/chatbot.py

@@ -32,15 +32,15 @@ class Chatbot:
         self.context_page_num = None
         self.context_file_name = None
 
-    def build_knowledge_base(self, files, upload_mode="僅作這次使用"):
+    def build_knowledge_base(self, files, upload_mode="once"):
         work_flow_controller = WorkFlowController(files, self.uid)
         self.csv_result_path = work_flow_controller.csv_result_path
         self.json_result_path = work_flow_controller.json_result_path
 
-        if upload_mode == "上傳至資料庫":
-            self.knowledge_base = self.__get_db_knowledge_base()
+        if upload_mode == "Upload to Database":
+            self.__get_db_knowledge_base()
         else:
-            self.knowledge_base = self.__get_local_knowledge_base()
+            self.__get_local_knowledge_base()
 
     def __get_db_knowledge_base(self):
         filename = "knowledge_base.csv"