print-preview: Fix typo from commit 31434612ce873fba3410bc38d9fbbb0a411b8a5e
Respect lockdown setting for page setup again

This apparently got broken when the page setup dialog was merged into
the general print dialog.

Based on eog commit 1bff58f772de4aad8cbf0886e46e1c26e075b54b
From Felix Riemann <friemann@gnome.org>
all: Fix a load of warnings

Partly based on eog commit 3859553433838e97367e7678f9da4ba2bcc7f973
From Cosimo Cecchi <cosimoc@gnome.org>