core: Define G_DEFINE_AUTOPTR_CLEANUP_FUNC for GDataQuery
core: Define G_DEFINE_AUTOPTR_CLEANUP_FUNC for GDataQuery

The cleanup function is not defined for GDataQuery, which prevents
G_DECLARE_DERIVABLE_TYPE use for its subclasses. Let's define it
so G_DECLARE_DERIVABLE_TYPE can be used in the subsequent commits.

GNOME/libgdata