upgrade node version to v17 on relay

[nicolasochem]

I tried but I got this:

│ Starting relay connected to node http://localhost:8732/                                                                                            │
│ [HPM] Proxy created: /  -> http://localhost:8732/                                                                                                  │
│ Starting to monitor block production.                                                                                                             │
│ Flashbake relay started on http://localhost:10732/                                                                                                 │
│ connect ECONNREFUSED ::1:8732                                                                                                                     │
│ Block monitor connection error: connect ECONNREFUSED ::1:8732                                                                                     │
│ Retrying constants request, retries left: 999                                                                                                     │
│ connect ECONNREFUSED ::1:8732

It's a permanent failure, not temporary.

It could be as simple as replacing localhost with 127.0.0.1 since I suspect ipv6 issue. I moved back to node v16 for now.