staff line-count greater than 5: how to prevent/hide line at left of staff

[Jeffery Shivers]

Hi,

I am using a staff with (many) more than five lines, but when I
increase the line-count a vertical line appears to the left of the
staff. How do I prevent that from happening, or at least make that
line transparent?

\version "2.19.54"

\score {
  \new Staff {
    \override Staff.StaffSymbol.line-count = #6
    c'4
  }
}

-- 

Jeffery Shivers
 jefferyshivers.com
 soundcloud.com/jefferyshivers