Need to gracefully handle username registration failures
Issue generated from Tuleap's migration script. Originally submitted by: Maxim Cournoyer (mcournoyer)
GNU/Linux Ubuntu 16.04 amd64
* Reproduce steps (Gnome client):
- Go to settings.
- Create a new account *without* registering a public username.
- In the "General" tab of the newly created account, enter the name service URL of a server on which the Ethereum miner was purposefully stopped.
- Enter an available username in the "Username" text box.
- Click on the Register button.
- The username is now frozen (non-editable) and cannot be registered again nor changed for the account.
* Expected results:
- The software should detect that the registration did not happen, and warn about it.
- The user should be allowed to retry registering the username (or a different, available one) until it succeeds.