Switch Utopia license to CC-BY-NC-SA 3.0

Summary:
Per https://utopia.espace-win.org/w/index.php?oldid=259

Ref T1376

Test Plan:
Wiki shows with the right icon the following text:
« Le contenu est disponible sous licence Attribution-NonCommercial-ShareAlike 3.0 Unported sauf mention contraire. »

Reviewers: dereckson

Maniphest Tasks: T1376

Differential Revision: https://devcentral.nasqueron.org/D1515