Adding back the dependency on restconf in the authz feature

This is the second half of the post-Helium master version bump. It puts
the dependency from the authz feautre onto the restconf feature back in.

Change-Id: Ibe1da210147490acfcfaebf8d93dcd99c998587e
Signed-off-by: Colin Dixon <colin@colindixon.com>