This is to ease backporting to Debian bullseye, where pdfxup writes
status output to stdout.

pdfnup was removed some time in 2021; pdfxup has always been around.

This is important in scenarios where AleKSIS, due to a race condition,
references something like a stale S3 content object. impressive-display
should log this and, most importantly, not try to handle the rror
output as display file.