Key signature not displaying correctly on clef change at the start of a score
When using one clef for the stave, but using a different one for the first note, the key signature will be wrong (see example below).
Steps to reproduce:
1. Make a new score with a key signature and any clef.
2. Place a note on the stave.
3. Drag a different clef to that note.
4. The key signature changes unexpectedly
Expected result (first), and actual result (second):
Using version 2.1.0, revision 871c8ce