Is reproducible  for openstack-3.7 only:

```
$ openstack-3.7 server list
issubclass() arg 1 must be a class
```


```
Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/cliff/app.py", line 400, in
run_subcommand
    result = cmd.run(parsed_args)
  File "/usr/lib/python3.7/site-packages/osc_lib/command/command.py", line 41,
in run
    return super(Command, self).run(parsed_args)
  File "/usr/lib/python3.7/site-packages/cliff/display.py", line 119, in run
    self.produce_output(parsed_args, column_names, data)
  File "/usr/lib/python3.7/site-packages/cliff/lister.py", line 82, in
produce_output
    parsed_args,
  File "/usr/lib/python3.7/site-packages/cliff/formatters/table.py", line 101,
in emit_list
    self.add_rows(x, column_names, data)
  File "/usr/lib/python3.7/site-packages/cliff/formatters/table.py", line 80,
in add_rows
    first_row = next(data_iter)
  File "/usr/lib/python3.7/site-packages/openstackclient/compute/v2/server.py",
line 1326, in <genexpr>
    ) for s in data))
  File "/usr/lib/python3.7/site-packages/osc_lib/utils/__init__.py", line 495,
in get_item_properties
    if issubclass(formatter, cliff_columns.FormattableColumn):
  File "/usr/lib64/python3.7/abc.py", line 143, in __subclasscheck__
    return _abc_subclasscheck(cls, subclass)
TypeError: issubclass() arg 1 must be a class
clean_up ListServer: issubclass() arg 1 must be a class
Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/osc_lib/shell.py", line 135, in run
    ret_val = super(OpenStackShell, self).run(argv)
  File "/usr/lib/python3.7/site-packages/cliff/app.py", line 279, in run
    result = self.run_subcommand(remainder)
  File "/usr/lib/python3.7/site-packages/osc_lib/shell.py", line 175, in
run_subcommand
    ret_value = super(OpenStackShell, self).run_subcommand(argv)
  File "/usr/lib/python3.7/site-packages/cliff/app.py", line 400, in
run_subcommand
    result = cmd.run(parsed_args)
  File "/usr/lib/python3.7/site-packages/osc_lib/command/command.py", line 41,
in run
    return super(Command, self).run(parsed_args)
  File "/usr/lib/python3.7/site-packages/cliff/display.py", line 119, in run
    self.produce_output(parsed_args, column_names, data)
  File "/usr/lib/python3.7/site-packages/cliff/lister.py", line 82, in
produce_output
    parsed_args,
  File "/usr/lib/python3.7/site-packages/cliff/formatters/table.py", line 101,
in emit_list
    self.add_rows(x, column_names, data)
  File "/usr/lib/python3.7/site-packages/cliff/formatters/table.py", line 80,
in add_rows
    first_row = next(data_iter)
  File "/usr/lib/python3.7/site-packages/openstackclient/compute/v2/server.py",
line 1326, in <genexpr>
    ) for s in data))
  File "/usr/lib/python3.7/site-packages/osc_lib/utils/__init__.py", line 495,
in get_item_properties
    if issubclass(formatter, cliff_columns.FormattableColumn):
  File "/usr/lib64/python3.7/abc.py", line 143, in __subclasscheck__
    return _abc_subclasscheck(cls, subclass)
TypeError: issubclass() arg 1 must be a class

END return value: 1
```