When converting an issue to sub-task in French, the titles contain translation error

Steps to get to the error:
1- Change the language to French and open an issue other than sub-task
2- Click on 'More', then 'Convert to sub-task'

The title for each step contain errors.
Actual: Etape 1 sur 4
Suggested: Étape 1 de 4

The same for steps 2 to 4.