git-gui: use "untracked" for files which are not known to git

"untracked" is the right phrase for files new to git. For example
git-status uses this phrase. Also make the question shorter.

Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>
1 file changed