Fix shouldLoadSaveAutocorrection.

Summary:
As QHash/QSet have not a stable odering, the test was failing all the time.
Let's use QCOMPARE on the sets itself and not relay on the exact xml
text output.

Test Plan: runTests successfully

Reviewers: KDE PIM, dvratil

Tags: KDE PIM

Differential Revision: https://phabricator.kde.org/D12414