fix(i18n): change from store.state.locale to store.state.i18n.locale

Author: hisasann

src/middleware/i18n.ts

@@ -30,7 +30,7 @@ export default function({
   }
   // Set locale
   store.commit('i18n/SET_LANG', locale)
-  app.i18n.locale = store.state.locale
+  app.i18n.locale = store.state.i18n.locale
   // If route is /<defaultLocale>/... -> redirect to /...
   // if (locale === defaultLocale && route.fullPath.indexOf('/' + defaultLocale) === 0) {
   //   const toReplace = '^/' + defaultLocale + (route.fullPath.indexOf('/' + defaultLocale + '/') === 0 ? '/' : '')

src/plugins/i18n.ts

@@ -11,7 +11,7 @@ export default ({ app, store }): void => {
   // Set i18n instance on app
   // This way we can use it in middleware and pages asyncData/fetch
   app.i18n = new VueI18n({
-    locale: store.state.locale,
+    locale: store.state.i18n.locale,
     fallbackLocale: 'ja',
     messages: {
       ja: require('~/locales/ja.json')