bug in snippet "Adding volta brackets to additional staves"

[Jean-Charles Malahieude]

Revising the French translation of repeats.itely, I notice that the 
volta bracket doesn't appear in the third staff of the snippet with the 
master branch.

Just compare the two versions of the online documentation of NR-1.41.1 
where the bracket is present on v2.22, but not on v2.23.

Copying Dan who worked on this matter.

Cheers,
--
Jean-Charles