When used with Protected Albums, preview image replacement is reversed

[EnigmaTriton]

When using Protected Albums plugin, one can replace the preview image of the album with a specific one (for privacy purpose for instance).
However, the modus theme does not behave correctly on this front (behavior is correct at least with clear, dark, elegant and its variants, stripped and its variants, and smartpocket themes).

Steps to reproduce

• In Piwigo, install modus theme and Protected Albums plugin (https://piwigo.org/ext/extension_view.php?eid=597)
• Protect some album by a password and set an alternate preview image for it.
• Look at the parent album (containing the protected one): the preview image is the original one.
• Open the protected album (as the admin who set it up): all preview images are the alternate preview.

ℹ️ When a guest enter the protected album and provides the password, the album correctly shows the preview images for the content.

Expected behavior

• When looking at the parent album, the preview image of the protected album is the alternate preview image set up by the Protected Albums plugin.
• When looking at the protected album as admin (without having to provide the password), the individual previews are the respective preview of each image.