[metacity] bump version to development version

[Alberts Muktupāvels <muktupavels src gnome org>]

commit f279fb395e2d3ef8857e52c40a3c224a79293874
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sat Jun 25 13:36:40 2016 +0300

    bump version to development version

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 392ce14..ccd4fe7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,7 +3,7 @@ dnl Define version info
 dnl **************************************************************************
 
 m4_define([m_major_version], [3])
-m4_define([m_minor_version], [20])
+m4_define([m_minor_version], [21])
 m4_define([m_micro_version], [0])
 m4_define([m_version], [m_major_version.m_minor_version.m_micro_version])