The notion of offline shouldn't be displayed in the editor when the backend does not support it

Reproduction steps

1. Open an electron instance
2. Click on edit on a page
3. Observe the bottom panel (just below the editor)

Expected

Nothing related to realtime is presented to the user

Actual

"Offline" is presented to the user.
Motivations to hide it: the user has no way to go online with this backend, therefore the information is just cluttering the UI.