automatic tests: do not embed EmbeddedImageData already in the library
Summary: should fix build failure due to D12320
Test Plan: build on Linux and tests are OK
Reviewers: dfaure, bcooksley, bruns, astippich
Reviewed By: dfaure
Subscribers: kde-frameworks-devel, Baloo
Tags: Frameworks, Baloo
Differential Revision: https://phabricator.kde.org/D13630