build: stop zoneinfo builder scripts changing '_' -> ' '

build: stop zoneinfo builder scripts changing '_' -> ' '

Zone names are correct when they contain an underscore, especially when
the zone names are used as input to functions and libraries.

See https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

e.g.

Africa/Addis_Ababa
Africa/Dar_es_Salaam
Pacific/Port_Moresby

This can be revised in future if some GUI aesthetic is required.

Signed-off-by: Paul Donald <[email protected]>