[MeshPart] Fix copy-paste error
[MeshPart] Fix copy-paste error

It doesn't make sense to check minLen and then call SetMinSize to maxLen
so this must be a copy-paste error.

Introduced in https://github.com/FreeCAD/FreeCAD/commit/f681b86abdddd55e2dcb80bc4612251570cc9b8b

Found with Coverity.
Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master