refactor: remove unnecessary appRouter

Author: leeyeh

src/init.js

@@ -90,9 +90,11 @@ AV.init = function init(options, ...params) {
   AV.setProduction(production);
   if (typeof disableCurrentUser !== 'undefined')
     AV._config.disableCurrentUser = disableCurrentUser;
-  AV._appRouter = new AppRouter(AV);
   const disableAppRouter =
     _disableAppRouter || typeof serverURLs !== 'undefined';
+  if (!disableAppRouter) {
+    AV._appRouter = new AppRouter(AV);
+  }
   AV._setServerURLs(
     extend(
       {},

src/request.js

@@ -123,7 +123,9 @@ const request = ({
   if (!(AV.applicationId && (AV.applicationKey || AV.masterKey))) {
     throw new Error('Not initialized');
   }
-  AV._appRouter.refresh();
+  if (AV._appRouter) {
+    AV._appRouter.refresh();
+  }
   const { requestTimeout: timeout } = AV._config;
   const url = createApiUrl({ service, path, version });
   return setHeaders(authOptions, signKey).then(headers =>