After removing the user that edited (but not created) a Landing Page Content Object, this Landing Page's "Versions" view (on the top bar, next to "Options") displays 0 versions. Also, the following error is shown: "Cannot load preview content versions info".

Steps to reproduce

1. Create a new installation of eZ Platform EE.
2. In the Platform UI, create new User in the "Administrator users" User Group with login "test_admin".
3. Log out and log in again as "test_admin".
4. Edit "Home" Landing Page Content Object and publish the new version.
5. Log out and log in again as "admin".
6. Delete User "test_admin".
7. Open "Home" in Landing Page Editor.
8. You will be presented with an error "Cannot load preview content versions info". The "Versions" view (on the top bar, next to "Options") will not display any versions.

NOTE: probably not having permissions to read the creator's data also will result in the same error, so the editor probably doesn't have to be deleted.
Also, the error probably will be present if any version is published by the deleted editor - it probably doesn't have to be the last published version.