patch 8.2.0636: :messages does not show the maintainer when $LANG is unset

Problem:    :messages does not show the maintainer when $LANG is unset.
Solution:   Call get_mess_lang() if available. (closes #5978)
diff --git a/src/version.c b/src/version.c
index 2fcabeb..7c753e2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    636,
+/**/
     635,
 /**/
     634,