Blacklist tst_MacGui::nonModalOrder

The test is marked as expected failure for the last 3 years, in CI it
is proven to be somehow flaky and it is failing now because of XPASS
which is not covered by blacklist feature.

This patch extends efforts of 7eba6d039d
and 03b4838cb5 by blacklisting the test
completely.

Change-Id: Ia295d61620fa6bc97b168d4de9456a18ed5c064f
Task-number: QTQAINFRA-1333
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

tests/auto/other/macgui/BLACKLIST

@@ -1,3 +1,2 @@
 [nonModalOrder]
-osx-10.11 ci
-osx-10.12 ci
+osx

tests/auto/other/macgui/tst_macgui.cpp

@@ -190,7 +190,6 @@ void tst_MacGui::nonModalOrder()
     primary.resize(400, 400);
     primary.move(100, 100);
     primary.exec();
-    QEXPECT_FAIL("", "Non-modal child windows show behind the modal dialig", Abort);
     QCOMPARE(primary.frontWidget, primary.secondaryWindow);
 }