Mailgun webhooks: AttributeError 'NoneType' object has no attribute 'get'

[izimobil]

In certain cases delivery-status can be None in the event POST data sent to the webhook. Anymail does not handle this case and throws an AttributeError.

• Anymail version: 9.1
• ESP (Mailgun, SendGrid, etc.): mailgun
• Versions of Django, requests, python:

  Django 3.2
  Requests 2.31.0
  Python 3.11

• Exact error message and/or stack trace

  
  AttributeError
     at /anymail/mailgun/tracking/
  'NoneType' object has no attribute 'get'

Request Method: | POST https://redacted.org/anymail/mailgun/tracking/ 3.2 AttributeError 'NoneType' object has no attribute 'get' /home/redacted/VirtualEnvs/redacted.org/lib/python3.9/site-packages/anymail/webhooks/mailgun.py, line 179, in esp_to_anymail_event

[medmunds]

(Fix released in Anymail 10.3)