OSX: Final cleanup for #60729

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk@60730 954f8c5b-7b00-dc11-b283-0030488c597c
Fix for a bug in StrokeCleaner identified through a discussion for Bug #36425 (freestyle edge marks not working).
Many thanks for Anthony Edlin who helped fix the issue.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk@60731 954f8c5b-7b00-dc11-b283-0030488c597c