Use FastGPT app opener for greetings

config/fastgpt.example.json

@@ -45,9 +45,7 @@
     "user_speech_timeout_sec": 0.2
   },
   "agent": {
-    "system_prompt": "FastGPT app owns the system prompt when send_system_prompt is false.",
-    "greeting": "您好，这里是无锡交警，我将为您远程处理交通事故。请将人员撤离至路侧安全区域，开启危险报警双闪灯、放置三角警告牌、做好安全防护，谨防二次事故伤害。若您已经准备好了，请点击继续办理，如需人工服务，请说转人工。",
-    "greeting_mode": "fixed"
+    "greeting_mode": "fastgpt_opener"
   },
   "services": {
     "stt": {
@@ -72,8 +70,7 @@
       "chat_id": null,
       "variables": {},
       "detail": false,
-      "timeout_sec": 60.0,
-      "send_system_prompt": false
+      "timeout_sec": 60.0
     },
     "tts": {
       "provider": "xfyun",