Fix the `postNode` function
It seems the logic of user id is incorrect in this function:
https://gitlab.iscpif.fr/gargantext/haskell-gargantext/blob/dev/src/Gargantext/API/Node/New.hs#L61
It seems the logic of user id is incorrect in this function:
https://gitlab.iscpif.fr/gargantext/haskell-gargantext/blob/dev/src/Gargantext/API/Node/New.hs#L61