Update NodeJS version in qooxdoo webkit to make sure osparc-simcore can be built

[JavierGOrdonnez]

@GitHK
This is a warning, since it's gonna explode in our faces.
We need to upgrade the base version of node-js in this image (used by osparc simcore to build the qooxdoo webkit) https://github.com/ITISFoundation/dockerfiles/blob/master/qooxdoo-kit/Dockerfile#L1

Users's can't build it on Windows WSL with ubuntu 20.04 LTS.

It's using node 10.x.x which received it's last patch on Apr 06, 2021

Error shows up when trying to run this line: https://github.com/ITISFoundation/dockerfiles/blob/master/qooxdoo-kit/Dockerfile#L1

PS note that this error seems to be flaky - after restarting his laptop, the user could run "make build" without errors.