MeshTools: fix test on build without assertions.
MeshTools: fix test on build without assertions.

DerThorsten/magnum,MiUishadow/magnum,MiUishadow/magnum,ashimidashajia/magnum,DerThorsten/magnum,MiUishadow/magnum,DerThorsten/magnum,MiUishadow/magnum,DerThorsten/magnum,DerThorsten/magnum,MiUishadow/magnum,ashimidashajia/magnum,MiUishadow/magnum,ashimidashajia/magnum,ashimidashajia/magnum,ashimidashajia/magnum