Bug#915722: gdal: fix build with poppler 0.71

[Jeremy Bicha]

Source: gdal
Version: 2.3.2+dfsg-3
Severity: important
Tags: patch

Debian may be updating its poppler version to 0.71 before the Buster
Transition Freeze. The current version of gdal in Debian fails to
build with the new poppler version.

I will submit a merge request at
https://salsa.debian.org/debian-gis-team/gdal/merge_requests in a few
minutes that fixes this issue.

Thanks,
Jeremy Bicha