Check http API and update nginx config

Before, Duniter was exposing two RPC APIs:

• http on 9933
• ws on 9944

And the nginx config serves both on https on 443 with path /http and /ws

It is used in cesium v2 to extract metadata: https://git.duniter.org/clients/cesium-grp/cesium2s/-/blob/ccf3d3113bfc25cdc6ae0d30a7c1e1b743120515/package.json#L52

It seems broken at the moment.

RML18