Fix django-suit NoneType is not iterable

[ecreality]

darklow/django-suit#633
https://docs.djangoproject.com/en/2.2/ref/contrib/admin/#django.contrib.admin.AdminSite.each_context

[codecov]

Codecov Report

Merging #111 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #111   +/-   ##
=======================================
  Coverage   78.47%   78.47%           
=======================================
  Files           4        4           
  Lines         432      432           
  Branches      103      103           
=======================================
  Hits          339      339           
  Misses         69       69           
  Partials       24       24

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[coveralls]

Coverage decreased (-0.1%) to 85.114% when pulling 64fd5b2 on CreativeQualityGranada:master into fbf322f on jedie:master.

[jedie]

Thanks for contribution.

[jedie]

it's included in the v0.9 release: https://pypi.org/project/django-reversion-compare/0.9.0/