fix fetching metadata and typegen

To fetch metadata we can now use the 9944 port directly which supports both http and websocket API.

In the package.json, the escape sequence was breaking curl command.

I also ran typegen against a more recent version of the runtime because I'm targeting develop branch that should be used on a recent build (we should fix nodes/rust/duniter-v2s#195 (closed) to allow easy develop environment with docker instead of fresh binary).

But the master branch should run npm run get:meta:prod which uses the current runtime available on the gdev network using the current API.

To summarize:

• old version of client listen on 9933 for http and 9944 for websocket
• matching nginx conf uses /http and /ws path respectively
• new client version listens only on 9944 for both "simple" http RPC and ws
• new client will be released for dev when issue 195 is fixed
• developement branch should use fresh runtime version even it is not yet published on gdev network
• gdev network should be updated more often to make beta testing easier (not maintaining multiple versions of the runtime)