[fednlp]when run "bash run_simulation.sh 5" , error "MPI_ABORT was invoked on......."

Hi Chaoyang! @chaoyanghe @yuchenlin
I try to reproduce some results in [FedNLP: Benchmarking Federated Learning Methods for Natural Language Processing Tasks](https://arxiv.org/abs/2104.08815).
I followed this [instruction](https://github.com/FedML-AI/FedML/tree/master/python/app/fednlp) step by step.
I met some troubles：
Backend: when using default hyperparameters in `text_classificationconfig/fedml_config_mpi.yaml` The data of each client is
learned and the loss can be reduced to low. But at the end of the aggregation, there will be and an fatal error：
- backend is `MPI`, it will output:
```
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 3 in communicator MPI_COMM_WORLD
with errorcode 0.

NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.
--------------------------------------------------------------------------
```
as the same with [https://github.com/FedML-AI/FedNLP/issues/35](https://github.com/FedML-AI/FedNLP/issues/35)
This will lead to kill the MPI and can not save the model.
- backend is `sp`, it will output:

```
[FedML-Server(0) @device-id-0] [Sat, 01 Oct 2022 18:30:34] [ERROR] [mlops_runtime_log.py:34:handle_exception] Uncaught exception
Traceback (most recent call last):
File "torch_main.py", line 57, in
fedml_runner.run()
File "/home/tao/anaconda3/envs/fednlp/lib/python3.8/site-packages/fedml/runner.py", line 123, in run
self.runner.run()
File "/home/tao/anaconda3/envs/fednlp/lib/python3.8/site-packages/fedml/simulation/simulator.py", line 67, in run
self.fl_trainer.train()
File "/home/tao/anaconda3/envs/fednlp/lib/python3.8/site-packages/fedml/simulation/sp/fedopt/fedopt_api.py", line 115, in train
w = client.train(w_global)
File "/home/tao/anaconda3/envs/fednlp/lib/python3.8/site-packages/fedml/simulation/sp/fedopt/client.py", line 29, in train
self.model_trainer.train(self.local_training_data, self.device, self.args)
File "/home/tao/anaconda3/envs/fednlp/lib/python3.8/site-packages/fedml/ml/trainer/my_model_trainer_classification.py", line 39, in train
for batch_idx, (x, labels) in enumerate(train_data):
ValueError: too many values to unpack (expected 2)
-------------------------------------------------------
Primary job terminated normally, but 1 process returned
a non-zero exit code.. Per user-direction, the job has been aborted.
-------------------------------------------------------
--------------------------------------------------------------------------
mpirun detected that one or more processes exited with non-zero status, thus causing
the job to be terminated. The first process to do so was:

Process name: [[18613,1],5]
Exit code: 1
```

- backend is `NCCL`, it will output:
```
ModuleNotFoundError: No module named 'fedml.simulation.nccl'
-------------------------------------------------------
Primary job terminated normally, but 1 process returned
a non-zero exit code.. Per user-direction, the job has been aborted.
-------------------------------------------------------
--------------------------------------------------------------------------
mpirun detected that one or more processes exited with non-zero status, thus causing
the job to be terminated. The first process to do so was:

Process name: [[16906,1],0]
Exit code: 1
--------------------------------------------------------------------------
```

I try to git clone the previous fednlp repository, and then git rolling back the fednlp and fedml packages to the [two months ago version](https://github.com/FedML-AI/FedNLP), which still has the problem that the model trained by MPI_ABORT cannot be [saved],(https://github.com/FedML-AI/FedNLP/issues/35) which is also the same error.

I would appreciate your help. Thanks.