tst_qopenglwidget fails on OpenSuSE

Test fails if the resolution is 800*600

QtQA::App::TestRunner: begin tst_qopenglwidget: [./tst_qopenglwidget] [-silent] [-o] [/work/ci/qt/qt5/dev/_artifacts/test-logs/tst_qopenglwidget-testresults-00.xml,xml] [-o] [-,txt]
Testing tst_QOpenGLWidget
FAIL! : tst_QOpenGLWidget::clearAndGrab() 'w->m_resizeOk' returned FALSE. ()
Loc: [tst_qopenglwidget.cpp(115)]
Totals: 10 passed, 1 failed, 0 skipped, 0 blacklisted
QtQA::App::TestRunner: test failed, running again to see if it is flaky...

• • • • • • • • • Start testing of tst_QOpenGLWidget *********

Totals: 10 passed, 1 failed, 0 skipped, 0 blacklisted

• • • • • • • • • Finished testing of tst_QOpenGLWidget *********
                  QtQA::App::TestRunner: test failure could be reproduced twice consecutively
                  QtQA::App::TestRunner: end tst_qopenglwidget: 6 seconds, exit code 1
                  QtQA::App::TestScheduler: tst_qopenglwidget failed; run concurrently with tst_qnetworkproxyfactory, tst_qfilesystemwatcher, tst_qopengl, tst_qmlvisual, [9 other tests], tst_qparallelanimationgroup, tst_qparallelanimationgroupjob, tst_qpathclipper