Problem:
The scope `elseif $LC_MESSAGES =~ '\a\a' || $LC_MESSAGES ==# "C"` in
function `s:Locale` in file `runtime/autoload/tutor.vim` leaves a case
when l:lang is not defined.
Solution:
Define `l:lang` at function scope instead of `if` scope
(cherry picked from commit e5665754d1)
0c2bf55e90
