Retire message catalog of nvi

[Rin Okuyama <rokuyama%rk.phys.keio.ac.jp@localhost>]

Hi,

Does anyone use message catalog of nvi? If it is not, I would like to
disable it and stop installing catalog files.

Messages contain printf(3) format strings. When they are inconsistent
with C sources, a segmentation fault can occur if worse. I found an
inconsistency at least for #038 in ru_RU.KOI8-R.base.

Catalog files have been untouched long years except for a case where
messages about machchars option were added for some languages, not all.
If we decide to keep them, we should consider how to check them
systematically.

Note that OpenBSD has already removed them. I feel this is a reasonable
choice, although I do not always agree with their ways of radicalism ;-).

rin