Allow to build against poppler master

Summary:
Poppler dev increases version when they
release it. Not before. So we can't find 0.72.
We need to check compile to be sure.

Test Plan: Compile :)

Reviewers: vkrause

Reviewed By: vkrause

Subscribers: kde-pim

Tags: KDE PIM

Differential Revision: https://phabricator.kde.org/D17229