Details
Description
When attempt to create a Region or Participant which already exists we get InternalError instead of user-friendly error message. It seems that django.modelAdmin does not check the unique_together constraint on these models when creating new objects.
https://gerrit.sio2project.mimuw.edu.pl/1451
SIO-1138No InternalError when creating an existing Region or ParticipantChange-Id: I17f566ce1d2dc72207324863551aaad77b47deab