Browsers autofill username in Forum image field

Under circumstances which may be browser specific, the "Forum image" field in ACP, Forums, Settings is autofilled with the administrative user's username, presumably because immediately below the Forum image field is a field for a forum password, labeled "Password", so the browser assumes that the immediately preceding field is for a username.

The solution might be as simple as moving the Forum password field, but that is beyond my pay grade.