Articulations too far from some beamed notes on drum staves

1) new score for drumset
2) add eighth notes A D (snare, ride)
3) flip beam down by selecting either note and pressing "X"
4) add accents to both notes

Result: accents placed way too high above:

The initial stem layout has the stems up, which is normal, but they should have been corrected during initial beam layout. Unfortunately this doesn't happen for drum staves, and they get added to the skyline as upstems. This is corrected later in the second beam layout, but it's too late for the skyline.

Fix is simple, PR forthcoming.