Doc: Replace question mark with fullstop (GH-99558)

The sentence "Set the LC_CTYPE locale to the user preferred locale." should end with a period
instead of a question mark.
(cherry picked from commit 0e09d2cc59cad61ad6a7a79aade52e9a2cfa7b34)

Co-authored-by: Rafael Fontenelle <rffontenelle@users.noreply.github.com>