[Trunk] Clef issues with Delete selected measures on first bar of 1.0 score
Using MuseScore 1.0:
1. Create piano score.
2. Enter some notes.
Using MuseScore 2.0 Nightly Build (4387):
4. Open score.
5. Drag-select a note in the first bar.
6. Delete selected measures.
(Result: Everything is treble clefs.)
(Result: The second bar onwards is all treble clefs, but the original clefs at the beginning have restored.)