[sysprof] build: bump gtk+ requirement

[Christian Hergert <chergert src gnome org>]

commit bfb2c20071af8f0fe777903cd2ad9691691753db
Author: Christian Hergert <chergert redhat com>
Date:   Thu Sep 1 21:36:33 2016 -0700

    build: bump gtk+ requirement
    
    Really, we require what will be .6, as the commit is only in master for
    propagation of natural width.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 1efe99d..cb96c7a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -112,7 +112,7 @@ dnl ***********************************************************************
 dnl Check for required packages
 dnl ***********************************************************************
 m4_define([glib_required_version], [2.44.0])
-m4_define([gtk_required_version], [3.21.4])
+m4_define([gtk_required_version], [3.21.5])
 m4_define([systemd_required_version], [222])
 
 PKG_CHECK_MODULES(GIO,