fixed curvefit failings for the first windows
fixed curvefit failings for the first windows

shikhar413/openmc,amandalund/openmc,walshjon/openmc,shikhar413/openmc,walshjon/openmc,mit-crpg/openmc,mit-crpg/openmc,amandalund/openmc,shikhar413/openmc,paulromano/openmc,walshjon/openmc,amandalund/openmc,walshjon/openmc,paulromano/openmc,paulromano/openmc,shikhar413/openmc,mit-crpg/openmc,mit-crpg/openmc,amandalund/openmc,paulromano/openmc