gio/tests: Don't depend on a data file that's not built
gio/tests: Don't depend on a data file that's not built

data.gresource is not built when cross-compiling: Don't
add it to test_data in that case.

https://bugzilla.gnome.org/show_bug.cgi?id=757628

johne53/MB3Glib,mzabaluev/glib,ieei/glib,johne53/MB3Glib,mzabaluev/glib,johne53/MB3Glib,endlessm/glib,johne53/MB3Glib,Distrotech/glib,ieei/glib,mzabaluev/glib,MathieuDuponchelle/glib,Distrotech/glib,ieei/glib,johne53/MB3Glib,MathieuDuponchelle/glib,endlessm/glib,MathieuDuponchelle/glib,MathieuDuponchelle/glib,endlessm/glib,Distrotech/glib,mzabaluev/glib,ieei/glib,MathieuDuponchelle/glib,endlessm/glib,Distrotech/glib,endlessm/glib,mzabaluev/glib,johne53/MB3Glib,Distrotech/glib,ieei/glib