fix(locale): default user locale should be the server setting (#1574)

* fix(locale): default user locale should be the server setting

* fix(db): fix user settings migration

* fix(db): set default locale to empty string

* revert: revert change to usersettings.ts

src/components/UserProfile/UserSettings/UserGeneralSettings/index.tsx

@@ -95,7 +95,7 @@ const UserGeneralSettings: React.FC = () => {
       </div>
       <Formik
         initialValues={{
-          locale: data?.locale ?? 'en',
+          locale: data?.locale,
           displayName: data?.username,
           region: data?.region,
           originalLanguage: data?.originalLanguage,