Chord symbols do not scale with staff size

3.0.5 and 3.1 beta - something I missed in my update for small stave scaling.

1) new score
2) enter a chord symbol
3) staff properties on that staff
4) small
5) OK

Result: chord does not scale. At least, not right away - it does after editing, and chords come out small on reload. That's because we aren't calling render() on staff spatium change