[metacity] configure: add missing square brackets

[Alberts Muktupāvels <muktupavels src gnome org>]

commit ca837759e35d66ba5bb13dcdc41ba47e3dc1c974
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Wed Jun 28 18:13:14 2017 +0300

    configure: add missing square brackets

 configure.ac |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 9b0f3c9..240765f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -80,9 +80,9 @@ dnl **************************************************************************
 dnl Metacity version
 dnl **************************************************************************
 
-AC_DEFINE([METACITY_MAJOR_VERSION], m_major_version, [Metacity major version])
-AC_DEFINE([METACITY_MINOR_VERSION], m_minor_version, [Metacity minor version])
-AC_DEFINE([METACITY_MICRO_VERSION], m_micro_version, [Metacity micro version])
+AC_DEFINE([METACITY_MAJOR_VERSION], [m_major_version], [Metacity major version])
+AC_DEFINE([METACITY_MINOR_VERSION], [m_minor_version], [Metacity minor version])
+AC_DEFINE([METACITY_MICRO_VERSION], [m_micro_version], [Metacity micro version])
 
 dnl **************************************************************************
 dnl Check for required packages