patch 8.2.0639: MS-Windows: messages test still fails

Problem:    MS-Windows: messages test still fails.
Solution:   Filter out the maintainer message.
diff --git a/src/testdir/test_messages.vim b/src/testdir/test_messages.vim
index 3d7245d..5a2c64c 100644
--- a/src/testdir/test_messages.vim
+++ b/src/testdir/test_messages.vim
@@ -3,21 +3,27 @@
 source shared.vim
 source term_util.vim
 
-function Test_messages()
+" Get all messages but drop the maintainer entry.
+func GetMessages()
+  redir => result
+  redraw | messages
+  redir END
+  let msg_list = split(result, "\n")
+  if msg_list->len() > 0 && msg_list[0] =~ 'Messages maintainer:'
+    return msg_list[1:]
+  endif
+  return msg_list
+endfunc
+
+func Test_messages()
   let oldmore = &more
   try
     set nomore
-    " Avoid the "message maintainer" line.
-    let $LANG = ''
-    let $LC_ALL = ''
-    let $LC_MESSAGES = ''
-    let $LC_COLLATE = ''
 
     let arr = map(range(10), '"hello" . v:val')
     for s in arr
       echomsg s | redraw
     endfor
-    let result = ''
 
     " get last two messages
     redir => result
@@ -28,24 +34,19 @@
 
     " clear messages without last one
     1messages clear
-    redir => result
-    redraw | messages
-    redir END
-    let msg_list = split(result, "\n")
+    let msg_list = GetMessages()
     call assert_equal(['hello9'], msg_list)
 
     " clear all messages
     messages clear
-    redir => result
-    redraw | messages
-    redir END
-    call assert_equal('', result)
+    let msg_list = GetMessages()
+    call assert_equal([], msg_list)
   finally
     let &more = oldmore
   endtry
 
   call assert_fails('message 1', 'E474:')
-endfunction
+endfunc
 
 " Patch 7.4.1696 defined the "clearmode()" function for clearing the mode
 " indicator (e.g., "-- INSERT --") when ":stopinsert" is invoked.  Message
diff --git a/src/version.c b/src/version.c
index 3ba7452..70af7b0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    639,
+/**/
     638,
 /**/
     637,