Unreviewed GTK gardening. Adding failure expectation for a reftest added in r147111
that's failing due to subpixel layout being disabled on the GTK port.

* platform/gtk/TestExpectations:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147126 268f45cc-cd09-0410-ab3c-d52691b4dbfc