Git 2.19 ignores default system language in Mac (2.18 or earlier did not)

[Vasily Korytov]

Hi,

$ locale
LANG=
LC_COLLATE="C"
LC_CTYPE="UTF-8"
LC_MESSAGES="C"
LC_MONETARY="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_ALL=
$ uname -mrs
Darwin 16.7.0 x86_64
$ git --version
git version 2.19.0

In Mac’s system preferences I have three languages: English (default), Russian, 
Ukrainian.

After update to Git 2.19 Git’s output suddenly appeared in Russian.
I can use `export LANG=en_US.UTF-8` to switch it to English back, but it’s very 
weird.

Did not find any related things in changelog, so assuming this is a bug.