chore: Compatible with old compiler

packages/uni-app-plus/dist/uni-app-service.es.js

@@ -2156,7 +2156,7 @@ var serviceContext = (function (vue) {
   });
 
   function initI18n() {
-      const localeKeys = Object.keys(__uniConfig.locales);
+      const localeKeys = Object.keys(__uniConfig.locales || {});
       if (localeKeys.length) {
           const i18n = useI18n();
           localeKeys.forEach((locale) => i18n.add(locale, __uniConfig.locales[locale]));

packages/uni-core/src/service/init/i18n.ts

@@ -2,7 +2,7 @@ import { BuiltInLocale } from '@dcloudio/uni-i18n'
 import { useI18n } from '../../i18n'
 
 export function initI18n() {
-  const localeKeys = Object.keys(__uniConfig.locales)
+  const localeKeys = Object.keys(__uniConfig.locales || {})
   if (localeKeys.length) {
     const i18n = useI18n()
     localeKeys.forEach((locale) =>