fix: keep the undefined data for AV.request

cocos2d-x-lite throws if we send {}

Author: leeyeh

src/request.js

@@ -116,7 +116,7 @@ const request = ({
   method,
   path,
   query,
-  data = {},
+  data,
   authOptions,
   signKey = true,
 }) => {
@@ -160,7 +160,7 @@ const _request = (
   className,
   objectId,
   method,
-  data = {},
+  data,
   authOptions,
   query
 ) => {