Can't remove spacer after reordering instruments
Bug seen in 2.2-dev (MuseScoreNightly-2017-06-14-2151-2.2-f79cf24.7z), in 2.1.0 and in 2.0.3
- Have at least two instruments
- add spacer to one staff
- reorder instruments
- spacer is not removable
To temporarily fix it reorder instruments as previously or (thanks to underquark) place another spacer on the same stave and then delete it.