Percent repeat killed after line wrap

[Roman Stawski]

> I'm not top posting.

When using percent repeats in a score with \RemoveEmptyStaffContext, 
repeated bars disappear after a line wrap.

====
\version "2.11.49"
\paper{ ragged-right=##t } 
\context StaffGroup <<

  \new Staff {
    \clef treble
    \time 6/8
    \relative c'' {
      \repeat unfold 8 { g8 g g g g g | }
    }
  }

  \new Staff {
    \clef bass
    \relative c {
      \repeat percent 4 { e4 r8 e4 r8  | c4 r8 c4 r8 | }
    }
  }

>>

\layout {
  \context { 
    \RemoveEmptyStaffContext 
  }
}
====