TpContact: use the generated #defines for token names
TpContact: use the generated #defines for token names

If we'd done this already, it would have caught the error fixed by the
previous commit.

Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib