Comment 1 for bug 2024136

Indeed in GitRepositoryEditView.setUpWidgets() we seem to make it `required = True` if it already exists:

```
if self.context.default_branch:
     self.widgets["default_branch"].context.required = True
```

I assume then when editing (not creating) this always exists already, so it doesn't make sense to have the '(Optional)' there when editing.