This reverts commit 12bb5092.

This change is causing compatibility issues with Consul 1.9.X;
I suspect the change is only compatible with Consul 1.10 or higher
which is not released yet, and not something Nomad can require
for quite some time.

E.g. when registering an ingress gateway,

```
consul.sync: failed to update services in Consul: error="Unexpected response code: 400 (Request decode failed: json: unknown field "TransparentProxy")"
```