switched timestep variables from double to int

// To do:

// Mysterious problem with   //  if (universe->iworld == 0) 

/* ----------------------------------------------------------------------

   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator

   http://lammps.sandia.gov, Sandia National Laboratories

  // Run NEB

  double beginstep_hold = update->beginstep;

  double endstep_hold = update->endstep;

  double ntimestep_hold = update->ntimestep;

  double nsteps_hold = update->nsteps;

  int beginstep_hold = update->beginstep;

  int endstep_hold = update->endstep;

  int ntimestep_hold = update->ntimestep;

  int nsteps_hold = update->nsteps;

  if (universe->me == 0) {

    universe->ulogfile = ulogfile_neb;