add quota config in dialog conf (#339)

### What problem does this PR solve?

Issue link:#337

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

api/apps/conversation_app.py

@@ -241,7 +241,7 @@ def chat(dialog, messages, **kwargs):
     chat_logger.info("User: {}|Assistant: {}".format(
         msg[-1]["content"], answer))
 
-    if knowledges:
+    if knowledges and prompt_config.get("quote", True):
         answer, idx = retrievaler.insert_citations(answer,
                                                    [ck["content_ltks"]
                                                        for ck in kbinfos["chunks"]],