Unable to update only password of admin account

**What happened**:

It seems there was a frontend bug while updating the admin account at the settings page.
The "SAVE" button is only activated if the given value in the "username" field is different from the current one.

**What you expected to happen**:

**How to reproduce it**:

**Environment**:
- `piped` version:
- `control-plane` version:
- Others:
