SpanBar joining Ossia & main staff no longer printed in 2.17

[Marc Mouries]

Hi Lilyponders,

I am typesetting a score with an ossia using the snippet: 

http://lsr.dsi.unimi.it/LSR/Snippet?id=125

In version 2.16, this snippet print a spanBar joining the ossia and the main staff. 

In 2.17, the following warning is printed in the logs:

warning: No span bar glyph defined for bar glyph ':'; ignoring.

I haven't seen described in the changes page and in the doc how to migrate

	\override SpanBar #'glyph-name = #":"

-- Marc