job resize to zero node count error

When a job size was reset to zero, this error message was printed:
slurm_allocation_lookup: Job/step already completing or completed
which may lead the user to believe the operation failed when it
worked as planned. Now it prints this:
To reset Slurm environment variables, execute
  For bash or sh shells:  . ./slurm_job_43565_resize.sh
  For csh shells:         source ./slurm_job_43565_resize.csh
Where the reset scripts contain zero node count information:
export SLURM_NODELIST=""
export SLURM_JOB_NODELIST=""
export SLURM_NNODES=0
export SLURM_JOB_NUM_NODES=0
export SLURM_JOB_CPUS_PER_NODE=""
unset SLURM_NPROCS
unset SLURM_NTASKS
unset SLURM_TASKS_PER_NODE