jupyter_utils testing error

[wyli]

Describe the bug
error from the cron tests:
https://github.com/Project-MONAI/MONAI/runs/2372603948?check_suite_focus=true#step:6:681

Running ./modules/jupyter_utils.ipynb
Checking PEP8 compliance...
Running notebook...
Before:
    "max_epochs = 20\n",
After:
    "max_epochs = 1\n",

Executing:   0%|          | 0/19 [00:00<?, ?cell/s]
Executing:   5%|▌         | 1/19 [00:00<00:17,  1.01cell/s]
Executing:  16%|█▌        | 3/19 [00:04<00:19,  1.24s/cell]
Executing:  26%|██▋       | 5/19 [00:07<00:17,  1.24s/cell]
Executing:  37%|███▋      | 7/19 [00:08<00:12,  1.03s/cell]
Executing:  47%|████▋     | 9/19 [00:10<00:09,  1.01cell/s]
Executing:  79%|███████▉  | 15/19 [00:10<00:02,  1.41cell/s]
Executing:  79%|███████▉  | 15/19 [00:13<00:03,  1.13cell/s]
Traceback (most recent call last):
  File "/opt/conda/bin/papermill", line 8, in <module>
    sys.exit(papermill())
  File "/opt/conda/lib/python3.8/site-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/opt/conda/lib/python3.8/site-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/opt/conda/lib/python3.8/site-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/opt/conda/lib/python3.8/site-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/opt/conda/lib/python3.8/site-packages/click/decorators.py", line 21, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/opt/conda/lib/python3.8/site-packages/papermill/cli.py", line 250, in papermill
    execute_notebook(
  File "/opt/conda/lib/python3.8/site-packages/papermill/execute.py", line 122, in execute_notebook
    raise_for_execution_errors(nb, output_path)
  File "/opt/conda/lib/python3.8/site-packages/papermill/execute.py", line 234, in raise_for_execution_errors
    raise error
papermill.exceptions.PapermillExecutionError: 
---------------------------------------------------------------------------
Exception encountered at "In [7]":
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-7-b654e8190558> in <module>
----> 1 con.status()

/__w/MONAI/MONAI/monai/utils/jupyter_utils.py in status(self)
    321         stats = self.status_dict
    322 
--> 323         msgs = [stats.pop(StatusMembers.STATUS.value), "Iters: " + str(stats.pop(StatusMembers.ITERS.value))]
    324 
    325         for key, val in stats.items():

KeyError: 'Iters'