Bug 1080832 - [Messages][RTL] Cursor is badly located in recipients and subject when they are empty. r=julien

hey @eeejay do you remember why you added this in https://github.com/mozilla-b2g/gaia/pull/23013 ? From our point of view it's useless (because we programmatically give the focus if the user click in a blank space in the panel) but maybe you had a reason for a11y?

The consequence of this property is that a recipient being edited takes the whole available space. Without this property it takes only the space its content needs.