Begin of the insertion### Reproduction

Exact reproduction is unknown, the problem will not be easily reproducile (it occurs only rarely on known production systems).
A probable reproduction might be:

- have a work package
- edit the work package
- click the save button multiple times in quick succession

### Expected behaviour

- for each change of a work package, only a single journal entry is created
- there is only one row in the `journals` table of the database
- no two rows in that table are equal in `journable_type`, `journable_id` **and** `version`

### Actual behaviour

- it is possible that there are two equal journal entries
- two or more rows in `journals` can be equal in `journable_type`, `journable_id` **and** `version`End of the insertion