[BUG] Creating a salt-master vm on azurearm fails

following the cloud map guide, specifically the part on setting up new salt master https://docs.saltstack.com/en/latest/topics/cloud/map.html#setting-up-new-salt-masters, i have the map file:

azure_ubuntu:
  - smvm:
      make_master: True

backed up by the following profile:

azure_ubuntu:
  provider: my-azurearm-config
  image: Canonical|UbuntuServer|18.04-LTS|latest
  size: Basic_A0
  #location: westus
  #network: my_network
  #subnet: subnet
  #resource_group: my_rg
  allocate_public_ip: True
  ssh_username: azureuser
  ssh_publickeyfile: /root/.ssh/id_rsa.pub
  ssh_keyfile: /root/.ssh/id_rsa
  disable_password_authentication: True

Launching a regular instance works just fine however when make_master is True, salt-cloud trows the following error

[ERROR   ] There was a query error: dictionary update sequence element #0 has length 1; 2 is required
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/cloud/cli.py", line 352, in run
    ret = mapper.run_map(dmap)
  File "/usr/lib/python3/dist-packages/salt/cloud/__init__.py", line 2126, in run_map
    out = self.create(master_profile, local_master=local_master)
  File "/usr/lib/python3/dist-packages/salt/cloud/__init__.py", line 1242, in create
    output = self.clouds[func](vm_)
  File "/usr/lib/python3/dist-packages/salt/cloud/clouds/azurearm.py", line 1362, in create
    ret = __utils__["cloud.bootstrap"](vm_, __opts__)
  File "/usr/lib/python3/dist-packages/salt/utils/cloud.py", line 547, in bootstrap
    master_conf = master_config(opts, vm_)
  File "/usr/lib/python3/dist-packages/salt/utils/cloud.py", line 361, in master_config
    "master", vm_, opts, default={}, search_global=True
ValueError: dictionary update sequence element #0 has length 1; 2 is required

Reproduce the failure with the shown Azure ARM map and profile, then inspect salt/cloud/clouds/azurearm.py around create and salt/utils/cloud.py around bootstrap and master_config. Done means creating the salt master with make_master succeeds without the reported ValueError while regular Azure ARM instance creation continues to work.