Volta laid out incorrectly in measure with disabled header segments

1) use default empty score
2) remove line break from end of first system
3) add volta to measure five (formerly the first measure of second system)

Result: the bracket lays out after the disabled clef segment. Here is how it looks with notes:

It was this way in last beta, so not something that broke as a result of the recent fixes - just something not fixed. Other lines seem fine. If it's a simple fix in volta layout, I'll get it. Otherwise, not sure we want to risk any more fundamental changes in this area right now...