for simplexe p1, metricCorner sample only at 1 point


git-svn-id: https://geuz.org/svn/gmsh/trunk@19408 59c8cabf-10d6-4a28-b43f-3936b85956c4
git-svn-id: https://geuz.org/svn/gmsh/trunk@19409 59c8cabf-10d6-4a28-b43f-3936b85956c4
git-svn-id: https://geuz.org/svn/gmsh/trunk@19410 59c8cabf-10d6-4a28-b43f-3936b85956c4