Quick: fix test

/Users/erik/dev/qt5-stable/qtdeclarative/tests/auto/quick/qquickgridview/tst_qquickgridview.cpp:1561:60: warning: adding 'int' to a string does not append to the string [-Wstring-plus-int]
                    items << qMakePair(QString("new item " + j), QString::number(j));
                                               ~~~~~~~~~~~~^~~

Change-Id: I94bd952abf82a8f174772482330b5fdd636578ad
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
QML: fix warning in tests

Remove unused class field.

Change-Id: I90981546e33d4839a91c418a8746e6f2ebc3bf46
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>