bpls -D crashes with local single value

Created by: germasch

I used adios2::LocalValueDim to write a per-proc value in a test, and it appears to confuse bpls when using the -D option in the current release (tag v2.3.0).

Code to reproduce:

#include <adios2.h>

int main(int argc, char** argv)
{
  MPI_Init(&argc, &argv);
  auto comm = MPI_COMM_WORLD;
  int rank, size;
  MPI_Comm_rank(comm, &rank);
  MPI_Comm_size(comm, &size);
  
  adios2::ADIOS ad(comm, adios2::DebugON);

  adios2::IO bpio = ad.DeclareIO("writer");

  auto varRankLocal = bpio.DefineVariable<int>("RankLocal", {adios2::LocalValueDim});

  auto bpWriter = bpio.Open("test.bp", adios2::Mode::Write, comm);
  bpWriter.Put(varRankLocal, rank);
  bpWriter.Close();  

  MPI_Finalize();
  return 0;
}

After running it on two procs (though the same problem happens on a single proc):

[kai@macbook build-dbg (topic/adios2 *)]$ mpirun -n 2 src/libpsc/tests/test_adios2_local_single_value
[kai@macbook build-dbg (topic/adios2 *)]$ bpls -d test.bp
  int      RankLocal  scalar
    (0)    0 1

[kai@macbook build-dbg (topic/adios2 *)]$ bpls -d -D test.bp
  int      RankLocal  scalar
        step 0:
[Kais-MacBook-Pro-269:96320] *** Process received signal ***
[Kais-MacBook-Pro-269:96320] Signal: Segmentation fault: 11 (11)
[Kais-MacBook-Pro-269:96320] Signal code: Address not mapped (1)
[Kais-MacBook-Pro-269:96320] Failing at address: 0x0
[Kais-MacBook-Pro-269:96320] [ 0] 0   libsystem_platform.dylib            0x00007fff5e2c5f5a _sigtramp + 26
[Kais-MacBook-Pro-269:96320] [ 1] 0   libsystem_c.dylib                   0x00007fff966af1a8 __sF + 152
[Kais-MacBook-Pro-269:96320] [ 2] 0   bpls                                0x000000010162562e _ZN6adios25utils17printVariableInfoIiEEiPNS_4core6EngineEPNS2_2IOEPNS2_8VariableIT_EE + 750
[Kais-MacBook-Pro-269:96320] [ 3] 0   bpls                                0x0000000101621216 _ZN6adios25utils11doList_varsEPNS_4core6EngineEPNS1_2IOE + 3510
[Kais-MacBook-Pro-269:96320] [ 4] 0   bpls                                0x0000000101620257 _ZN6adios25utils6doListEPKc + 1655
[Kais-MacBook-Pro-269:96320] [ 5] 0   bpls                                0x000000010161f362 _ZN6adios25utils8bplsMainEiPPc + 2194
[Kais-MacBook-Pro-269:96320] [ 6] 0   bpls                                0x0000000101629579 main + 41
[Kais-MacBook-Pro-269:96320] [ 7] 0   libdyld.dylib                       0x00007fff5dfb7015 start + 1
[Kais-MacBook-Pro-269:96320] [ 8] 0   ???                                 0x0000000000000004 0x0 + 4
[Kais-MacBook-Pro-269:96320] *** End of error message ***
Segmentation fault: 11