When a user pushes a key to a Bourreau, if the push fails, they get redirected to the users index page

[prioux]

Users can push their special personal key to the Bourreaux. It's done in the My Account page.

If the Bourreau is disconnected/invalid, an error occurs and the users is redirected to /users which is a route not allowed for normal users.

Instead, an error message should be shown and the users should be redirected to the My Account page again.

Note: Handle gracefully the case when the users pushes to several Bourreaux at once.