Disallow adding key signature to non-pitch percussion
1. Create score featuring an instrument from non-pitch percussion.
2. Add a key signature to instrument, from the palette.
Expected result: Amending key signatures is disallowed for non-pitch instruments.
Actual result: I'm able to add a key signature.
Using MuseScore 1.0 and 2.0 Nightly Build (4531) - Windows XP SP3.