[metacity] Bump required version to 2.21.1

[Thomas James Alexander Thurman <tthurman src gnome org>]

commit 155c85ae8b999c607a27668498f540337d8be4a6
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Jul 15 15:53:10 2010 +0200

    Bump required version to 2.21.1
    
    Commit 15f273e7 uses API introduced in the current cycle, but I
    forgot to bump the version requirements.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=572332

 configure.in |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.in b/configure.in
index 1d2922b..6deb7c1 100644
--- a/configure.in
+++ b/configure.in
@@ -120,7 +120,7 @@ AC_MSG_RESULT([$with_gtk])
 
 case "$with_gtk" in
   2.0) GTK_API_VERSION=2.0
-       GTK_MIN_VERSION=2.20.0
+       GTK_MIN_VERSION=2.21.1
        CANBERRA_GTK=libcanberra-gtk
        ;;
   3.0) GTK_API_VERSION=3.0