Fix urls being escaped by admin

[Eagllus]

Fixes #289

[codecov-io]

Codecov Report

Merging #290 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #290      +/-   ##
==========================================
+ Coverage   90.12%   90.12%   +<.01%     
==========================================
  Files          44       44              
  Lines        2835     2836       +1     
==========================================
+ Hits         2555     2556       +1     
  Misses        280      280

Impacted Files	Coverage Δ
django_q/models.py	97.4% <100%> (+0.01%)	⬆️

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