Blender Git Loki

Fix T85230: Face Set Boundary automasking not working with dyntopo

Dyntopo does not have Face Sets implemented yet, so the entire mesh is
considered a single Face Set. In that case, the check unique face set
function should always return true.

Reviewed By: JacquesLucke

Maniphest Tasks: T85230

Differential Revision: https://developer.blender.org/D10259