fix(emby): throw the right error message if no library exists (#1415)

This PR fixes a bug where the error message when no library exists was not displayed because of a
Jellyfin-specific check failing with Emby.

server/routes/settings/index.ts

@@ -352,7 +352,7 @@ settingsRoutes.get('/jellyfin/library', async (req, res, next) => {
       const account = await jellyfinClient.getUser();
 
       // Automatic Library grouping is not supported when user views are used to get library
-      if (account.Configuration.GroupedFolders.length > 0) {
+      if (account.Configuration.GroupedFolders?.length > 0) {
         return next({
           status: 501,
           message: ApiErrorCode.SyncErrorGroupedFolders,