ArraySourceTest: Use QTEST_GUILESS_MAIN

Authored by heikobecker on Dec 6 2019, 6:12 PM.

Description

ArraySourceTest: Use QTEST_GUILESS_MAIN

Summary: Allows the test to run without a display server.

Test Plan: Builds, test still passes

Reviewers: Frameworks, ahiemstra

Differential Revision: https://phabricator.kde.org/D25794