QTreeView is stretching the last section by default which was not
considered in this test. It worked by accident on linux because
there the default section size is 100 and the default window width
is also 100. On windows this was not the case and therefore the
test failed.
Task-number: QTBUG-51149
Change-Id: I9be1c1e942fc19817713773fe29d4afa93d73232
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>