Add support for latest noVNC version.

This small patch uses utils.js instead of vnc.js file (removed by upstream).
It also sets INCLUDE_URI to correct STATIC_URL variable in novnc.html template file.

This was tasted with latest noVNC and GWM code.

I've also made some changes in setup script and sent a pull request.
https://github.com/pbanaszkiewicz/ganeti_webmgr-setup/pull/9

I believe this patch closes: https://code.osuosl.org/issues/15189