azure service bus: fix TypeError when using Managed Identities

[marnikow]

When trying the new version of Kombu I get the following error:

TypeError("argument of type 'DefaultAzureCredential' is not iterable")
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/dist-packages/celery/worker/worker.py", line 202, in start
    self.blueprint.start(self)
  File "/usr/local/lib/python3.8/dist-packages/celery/bootsteps.py", line 112, in start
    self.on_start()
  File "/usr/local/lib/python3.8/dist-packages/celery/apps/worker.py", line 135, in on_start
    self.emit_banner()
  File "/usr/local/lib/python3.8/dist-packages/celery/apps/worker.py", line 169, in emit_banner
    ' \n', self.startup_info(artlines=not use_image))),
  File "/usr/local/lib/python3.8/dist-packages/celery/apps/worker.py", line 230, in startup_info
    conninfo=self.app.connection().as_uri(),
  File "/usr/local/lib/python3.8/dist-packages/kombu/connection.py", line 715, in as_uri
    return self.transport.as_uri(
  File "/usr/local/lib/python3.8/dist-packages/kombu/transport/azureservicebus.py", line 484, in as_uri
    if ":" in credential:
TypeError: argument of type 'DefaultAzureCredential' is not iterable

Since I don't understand the meaning of the as_url function I just fixed the error locally. Feedback is welcome :)

[auvipy]

this looks good, but It will need some time on my side to do a proper review

[auvipy]

we might not need the print output on the final version

[auvipy]

also can you please check if the rtd docs build failures is not related to this PR?

[50-Course]

also can you please check if the rtd docs build failures is not related to this PR?

Going through the log file, I am only able to deduce that the error isn't related to this PR. At least not that I know of. By my understanding,

Problem in your project's configuration. No default configuration file found at repository's root. See https://docs.readthedocs.io/en/stable/config-file/

Seems to be an issue from the docs/conf.py which am yet to fully go through. The .readthedocs.yml configuration file seemed untouched as well. Please let me know if I am overlooking something.

CC: @auvipy

[auvipy]

thanks