The router_id parameter was removed from Neutron[1] and its support was
removed from puppet-neutron long ago[2]. The transformer has not been
used since then.
[1] 448bc8e5220d3633f9c9ee804de0a38c2d829d78
[2] a30d2e7d77
Change-Id: I6ed1cc97cb7115bedcf0ee3204396828e8913835