QtBase: fix unit tests on Ubuntu 20

On Andreas' machine, the following unit tests are failing

The following tests FAILED:
219 - test_add_resource_options (Failed)
220 - test_wrap_cpp_options (Failed)
233 - test_testlib_no_link_gui (Failed)
234 - test_testlib_no_link_widgets (Failed)
266 - tst_qdbusabstractadaptor (Failed)
268 - tst_qdbusinterface (Failed)
287 - tst_qwindow (Failed)
310 - tst_qicon (Failed)
334 - tst_qfontdatabase (Failed)
337 - tst_qrawfont (Failed)
357 - tst_qtextmarkdownwriter (Failed)
374 - tst_qrhi (Failed)
376 - tst_qopengl (Failed)
389 - tst_http2 (Failed)
399 - tst_qhostinfo (Failed)
423 - tst_qprinter (Failed)
424 - tst_qprinterinfo (Failed)
466 - tst_qgraphicsview (Failed)
489 - tst_qwidget (Failed)
490 - tst_qwidget_window (Failed)
505 - tst_qsystemtrayicon (Failed)
506 - tst_qabstractbutton (Failed)
513 - tst_qdatetimeedit (Failed)
524 - tst_qlineedit (Failed)
552 - tst_qopenglwidget (Failed)
Errors while running CTest