[updater] check() always return object and is never null

On: Tauri 2.8.5 and tauri updater plugin 2.9.0

Check() function always return object with empty data and only available: true, so checking if(update) == null like in docs doesnt work anymore... I updated tauri and this plugin and it broke my update functionality. I moved back to updater plugin 2.5.1 version and now it works as expected..

I didn't change anything on my update server.