nic create/update without vlan id fails

[andy-maier]

Actual behavior

Certain operations on NICs such as "nic create" or "nic update" fail when the --vlan-id option is not specified.

For example:

$ zhmc nic create CPCB dal2-qz2-sr2-rk070-s21 --name IMGMT2 --description "Management port" --adapter MGMT2 --port 1 --device-number 1350
Traceback (most recent call last):
  File "/usr/local/bin/zhmc", line 8, in <module>
    sys.exit(cli())
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python3.6/dist-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/click/decorators.py", line 33, in new_func
    return f(get_current_context().obj, *args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/zhmccli/_cmd_nic.py", line 151, in nic_create
    cmd_ctx.execute_cmd(lambda: cmd_nic_create(cmd_ctx, cpc, partition,
  File "/usr/local/lib/python3.6/dist-packages/zhmccli/_helper.py", line 318, in execute_cmd
    cmd()
  File "/usr/local/lib/python3.6/dist-packages/zhmccli/_cmd_nic.py", line 152, in <lambda>
    options))
  File "/usr/local/lib/python3.6/dist-packages/zhmccli/_cmd_nic.py", line 418, in cmd_nic_create
    set_vlan_id(cmd_ctx, properties, org_options)
  File "/usr/local/lib/python3.6/dist-packages/zhmccli/_cmd_nic.py", line 498, in set_vlan_id
    properties['vlan-id'] = int(vlan_id)
TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType'

This can be circumvented by specifying --vlan-id "".

Expected behavior

Should work without having to specify --vlan-id "".

Execution environment

• zhmc version: 1.2.0
• zhmcclient version: 1.3.3
• Operating system (type+version): Ubuntu 18.04
• HMC version: z15
• CPC version: z15