When adding Steiner points in function tetgenmesh::reconstructmesh, they will always be part of the first region. However, in the function insertVerticesInRegion we now keep track of all the vertices which are really part of the first region and reset the mesh vertices of this region. When the generation of the mesh is then finished, and we want to have all the nodes in the model, the function GModel::rebuildMeshVertexCache will go over all the mesh vertices of all the entities in the model. As the Steiner points are now not inside any entity, they will not be taken into account. This commit will fix this.