Fix for SIGSEGV on Mandriva2008 in optimize mode only

Fix for SIGSEGV on Mandriva2008 in optimize mode only
==21300== Invalid read of size 4
==21300==    at 0x1445EA23: StdMeshers_Penta_3D::MakeVolumeMesh() (StdMeshers_Penta_3D.cxx:681)

  while (aItNodes->more()) {

It seems to be an error of optimization, aItNodes.px becomes invalid
before aItNodes->more() returns false but after the loop code is
performed for the last time.