Bracket adds space to margin even when hidden with empty staff

1. Open attached score, add a brace to the fourth staff, double-click and extend over the fifth staff.
2. Turn on "Hide empty staves."

Expected result: as the brace is not present, it won't take up space, so the left margin will be the same as before.

Actual result: unused extra space is added to the left margin (causing the line to break in a different place).