Fix TestCore::testRewriterTransactionRewriter

#0  0x02075525 in __cxa_throw () from /usr/lib/libstdc++.so.6
#1  0x0806e59c in QmlDesigner::RewriterView::applyChanges (this=0x84c4988) at /home/kkoehne/dev/creator/src/plugins/qmldesigner/core/model/rewriterview.cpp:416
#2  0x0806e172 in QmlDesigner::RewriterView::applyModificationGroupChanges (this=0x84c4988) at /home/kkoehne/dev/creator/src/plugins/qmldesigner/core/model/rewriterview.cpp:394
#3  0x0806e05a in QmlDesigner::RewriterView::customNotification (this=0x84c4988, identifier=...) at /home/kkoehne/dev/creator/src/plugins/qmldesigner/core/model/rewriterview.cpp:357
#4  0x0809380f in QmlDesigner::Internal::ModelPrivate::notifyCustomNotification (this=0x8339308, senderView=0x83b5308, identifier=..., nodeList=..., data=...)
    at /home/kkoehne/dev/creator/src/plugins/qmldesigner/core/model/model.cpp:330
#5  0x08063eb0 in QmlDesigner::AbstractView::emitCustomNotification (this=0x83b5308, identifier=..., nodeList=..., data=...) at /home/kkoehne/dev/creator/src/plugins/qmldesigner/core/model/abstractview.cpp:359
#6  0x08063e4b in QmlDesigner::AbstractView::emitCustomNotification (this=0x83b5308, identifier=..., nodeList=...) at /home/kkoehne/dev/creator/src/plugins/qmldesigner/core/model/abstractview.cpp:354
#7  0x08063dea in QmlDesigner::AbstractView::emitCustomNotification (this=0x83b5308, identifier=...) at /home/kkoehne/dev/creator/src/plugins/qmldesigner/core/model/abstractview.cpp:349
#8  0x080fbdfb in QmlDesigner::RewriterTransaction::commit (this=0xbfffe2ec) at /home/kkoehne/dev/creator/src/plugins/qmldesigner/core/rewritertransaction.cpp:60
#9  0x080fbd7b in ~RewriterTransaction (this=0xbfffe2ec, __in_chrg=<value optimized out>) at /home/kkoehne/dev/creator/src/plugins/qmldesigner/core/rewritertransaction.cpp:48
#10 0x081918ac in TestCore::testRewriterTransactionRewriter (this=0xbfffed90) at testcore.cpp:2140
#11 0x081d98a4 in TestCore::qt_metacall (this=0xbfffed90, _c=QMetaObject::InvokeMetaMethod, _id=84, _a=0xbfffe458) at moc_testcore.cpp:380
#12 0x01e24d5e in QMetaObject::metacall (object=0xbfffed90, cl=QMetaObject::InvokeMetaMethod, idx=88, argv=0xbfffe458) at kernel/qmetaobject.cpp:237
#13 0x01e2753c in QMetaMethod::invoke (this=0xbfffe5bc, object=0xbfffed90, connectionType=Qt::DirectConnection, returnValue=..., val0=..., val1=..., val2=..., val3=..., val4=..., val5=..., val6=..., val7=..., val8=...,
    val9=...) at kernel/qmetaobject.cpp:1568
#14 0x01e26aa2 in QMetaObject::invokeMethod (obj=0xbfffed90, member=0x833b8b0 "testRewriterTransactionRewriter", type=Qt::DirectConnection, ret=..., val0=..., val1=..., val2=..., val3=..., val4=..., val5=..., val6=...,
    val7=..., val8=..., val9=...) at kernel/qmetaobject.cpp:1148
#15 0x00cbaf6a in QMetaObject::invokeMethod (obj=0xbfffed90, member=0x833b8b0 "testRewriterTransactionRewriter", type=Qt::DirectConnection, val0=..., val1=..., val2=..., val3=..., val4=..., val5=..., val6=..., val7=...,
    val8=..., val9=...) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs.h:408
#16 0x00cb86c1 in qInvokeTestMethodDataEntry (slot=0x833b8b0 "testRewriterTransactionRewriter") at qtestcase.cpp:1244
#17 0x00cb8cb7 in qInvokeTestMethod (slotName=0x82055ce "testRewriterTransactionRewriter()", data=0x0) at qtestcase.cpp:1352
#18 0x00cb931c in qInvokeTestMethods (testObject=0xbfffed90) at qtestcase.cpp:1497
#19 0x00cb9a94 in QTest::qExec (testObject=0xbfffed90, argc=2, argv=0xbfffee64) at qtestcase.cpp:1716
#20 0x081cf627 in main (argc=2, argv=0xbfffee64) at testcore.cpp:6657