Tuplet numbers are not regularly aligned

[Pierre Perol-Schneider]

> I'm not top-posting
Hi Bug-squad,

See the Y-offset tuplet number difference here:

\version "2.19.83" % and "2.21"

\markup\italic "Output:"
\relative c''' {
  \tuplet 3/2 4 { b8 c d e f g }
}

\markup\italic "Attended output:"
\relative c''' {
  \tuplet 3/2 4 {
    b8 c d
    \once \override TupletNumber.Y-offset = #-1.35
    e f g }
}

Cheers,
Pierre