message: Make ex1 work again
diff: @@ -190,7 +190,7 @@ int main(int argc, char *argv[])
  }
  else
  {
  - a->AddDomainIntegrator(new Diffusion2Integrator(one));
  + a->AddDomainIntegrator(new DiffusionIntegrator(one));
  }
  // 9. Assemble the bilinear form and the corresponding linear system,
  