Id content is already used in the server template

[max-nextcloud]

https://github.com/nextcloud/server/blob/c10317f7f9f53a4de464915f754896eed7f1ee6c/core/templates/layout.user.php#L125 already makes use of the id content.

Make sure to have a unique id and to replace the correct dom element when mounting the vue app.