:art: fix global paramer `merchant`

src/res/values/api.json

@@ -1,4 +1,4 @@
 {
-    "api_url": "http://kid-app.lingjiao.cn",
+    "api_url": "https://kid-app.lingjiao.cn",
     "api_url_test": "http://tt-web.api.ai160.com"
 }

src/util/API/AJAXHelper.js

@@ -62,6 +62,7 @@ class AJAXHelper {
 		xmlHttpReq.setRequestHeader('uid', uid);
 		xmlHttpReq.setRequestHeader('sign', sign);
 		xmlHttpReq.setRequestHeader('terminal', platform);
+		xmlHttpReq.setRequestHeader('merchant', 'baby');
 		xmlHttpReq.setRequestHeader('requestId', requestId);
 		xmlHttpReq.setRequestHeader('Authentication', sign); //header中增加Authentication以兼容老版本
 		xmlHttpReq.setRequestHeader('Content-Type', 'application/' + (method == 'POST' || method == 'PUT' ? 'json' : 'text'));