message: fix use in serial with parallel build
diff: @@ -34,7 +34,9 @@ FindPointsGSLIB::FindPointsGSLIB()
  {
  gsl_comm = new comm;
  #ifdef MFEM_USE_MPI
  - MPI_Init(NULL, NULL);
  + int initialized;
  + MPI_Initialized(&initialized);
  + if (!initialized) { MPI_Init(NULL, NULL); }
  MPI_Comm comm = MPI_COMM_WORLD;;
  comm_init(gsl_comm, comm);
  #else
  