[dconf-editor] Fix build caused by GTK+ dependency

[Emmanuele Bassi <ebassi src gnome org>]

commit c02f7b7183b4f02ad243910c357bc16b5c4fe202
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon Jun 20 09:52:07 2016 +0100

    Fix build caused by GTK+ dependency
    
    Current GTK+ master is 3.21.2.
    
    This commit can be reverted once GTK+ 3.21.3 is released.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 1e18edc..855c53d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -32,7 +32,7 @@ APPSTREAM_XML
 # Dependencies
 DCONF_REQUIRED=0.25.1
 GLIB_REQUIRED=2.46.0
-GTK_REQUIRED=3.21.3
+GTK_REQUIRED=3.21.2
 
 PKG_CHECK_MODULES(DCONF_EDITOR, [
   glib-2.0 >= $GLIB_REQUIRED