[glib] README: Fix potentially extremely annoying typo

[Ryan Lortie <ryanl src gnome org>]

commit 37af8167b65ab95278262bd243292042d01a916b
Author: Ryan Lortie <desrt desrt ca>
Date:   Fri Jan 27 21:49:46 2012 +0100

    README: Fix potentially extremely annoying typo

 README.in |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/README.in b/README.in
index 6d53029..85c71a7 100644
--- a/README.in
+++ b/README.in
@@ -71,7 +71,7 @@ Notes about GLib 2.32
 
   or
 
-    G_MESSAGE_DEBUG=all
+    G_MESSAGES_DEBUG=all
 
 Notes about GLib 2.30
 =====================