ProxyService bugfix

[CawaAlreadyTaken]

[codecov[bot]]

Codecov Report

Attention: 4 lines in your changes are missing coverage. Please review.

Comparison is base (7db9aa1) 69.45% compared to head (ef35e60) 69.38%.

Files	Patch %	Lines
cms/service/ProxyService.py	0.00%	4 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1244      +/-   ##
==========================================
- Coverage   69.45%   69.38%   -0.07%     
==========================================
  Files         328      328              
  Lines       26196    26199       +3     
==========================================
- Hits        18195    18179      -16     
- Misses       8001     8020      +19     

Flag	Coverage Δ
functionaltests	46.95% <0.00%> (-0.26%)	:arrow_down:
unittests	56.68% <0.00%> (-0.04%)	:arrow_down:

Flags with carried forward coverage won't be shown. Click here to find out more.

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[wil93]

Can you explain how this bug gets triggered? It could be useful to know it so we can write a test for it.

[CawaAlreadyTaken]

While a contest is running, if the dataset for a task that does not belong to the running contest gets updated, the error is triggered. Se system keeps working, but the python Traceback for the Exception is written in the logs, visible from the admin Dashboard. I think task.contest_id should be used instead of task.contest.id.