coin_scraper.py violates UNIQUE constraint, tries to insert duplicate changes

 [ 1489475]    ERROR proc_update_tasks_needing_initial_details/root:  Unexpected Exception caught:
Traceback (most recent call last):
  File "/home/jimis/coin_scraper/coin_scraper.py", line 344, in looping_process
    target_func()
  File "/home/jimis/coin_scraper/coin_scraper.py", line 253, in proc_update_tasks_needing_initial_details
    db.update_tasks_changes(tasks_details)
  File "/home/jimis/coin_scraper/postgres_storage_backend.py", line 375, in update_tasks_changes
    self.curs.execute(query)
  File "/usr/lib/python3/dist-packages/psycopg2/extras.py", line 236, in execute
    return super().execute(query, vars)
psycopg2.errors.UniqueViolation: duplicate key value violates unique constraint "changes_unique_1"
DETAIL:  Key (project_n, branch_n, changeid, sha) = (2, 1, I1147978a05bfedb63037c7f4437921f85a6aabb1, ef7b855388876b990b53b1b37168f51dd6ddc3c0) already exists.