[mutter] Bump GTK+ required version to 2.91.7

[Owen Taylor <otaylor src gnome org>]

commit e884fc784e2b04b049dd4b162d5ebcc50f8d7c61
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Wed Dec 22 16:04:58 2010 -0500

    Bump GTK+ required version to 2.91.7

 configure.in |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.in b/configure.in
index dd6726c..5d5b78a 100644
--- a/configure.in
+++ b/configure.in
@@ -61,7 +61,7 @@ AC_CHECK_SIZEOF(__int64)
 ## byte order
 AC_C_BIGENDIAN
 
-GTK_MIN_VERSION=2.90.7
+GTK_MIN_VERSION=2.91.7
 CANBERRA_GTK=libcanberra-gtk3
 CANBERRA_GTK_VERSION=0.26