Re-enable qquicktextinput test on Mac OS X

Fixed in qtbase with commit 40b195d0f9ee7ef1b917a635bb073fa108b2ed40

Change-Id: I4af6080dde9c6356c11f09a6ded86ce9ce28b6e0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>