time signature gets printed twice if combined with acciaccatura

[Johannes Becker]

% time signature gets printed twice if combined with acciaccatura

PianoRHMusic = {
  \time 3/4
  \acciaccatura d'8
  c'2.
}
PianoLHMusic = {
  \time 3/4
  a2.
}
\include "satb.ly"

% Johannes