Autotests: Remove expectfail for test addRemoveItemsInModel

The bug QTBUG_30379 has been fixed.

Change-Id: Ic05f70e3dec528cacefba44d14a76952b5636315
Reviewed-by: Liang Qi <liang.qi@digia.com>

tests/auto/controls/data/tst_combobox.qml

@@ -289,11 +289,9 @@ TestCase {
         compare(comboBox.data[menuIndex].items.length, 3)
         comboBox.model.append({ text: "Tomato", color: "Red" })
         compare(comboBox.model.count, 4)
-        expectFailContinue('', 'QTBUG-30379')
         compare(comboBox.data[menuIndex].items.length, 4)
         comboBox.model.remove(2, 2)
         compare(comboBox.model.count, 2)
-        expectFailContinue('', 'QTBUG-30379')
         compare(comboBox.data[menuIndex].items.length, 2)
         comboBox.destroy()
     }