wordcount: do not rely on english in old versions

for older Vims, the wordcount extension falls back to `g<c-g>` and
parses the messaage that is generated.

When doing so, it expects the English locale, which might not be true.
Therefore, try to regex parse the result without using the english words
(assuming the output is still in the same order as in English).

autoload/airline/extensions/wordcount.vim

@@ -12,8 +12,8 @@ if exists('*wordcount')
 else  " Pull wordcount from the g_ctrl-g stats
   function! s:get_wordcount(visual_mode_active)
     let pattern = a:visual_mode_active
-          \ ? 'Lines; \zs\d\+\ze of \d\+ Words;'
-          \ : 'Word \d\+ of \zs\d\+'
+          \ ? '^.\D*\d\+\D\+\d\+\D\+\zs\d\+'
+          \ : '^.\D*\%(\d\+\D\+\)\{5}\zs\d\+'
 
     let save_status = v:statusmsg
     if !a:visual_mode_active && col('.') == col('$')