[nautilus] configure: bump gtk version requirement

[Carlos Soriano Sánchez <csoriano src gnome org>]

commit d3d7cce134a7147861c999d45549a48b1420a8fb
Author: Carlos Soriano <csoriano gnome org>
Date:   Thu Sep 8 21:18:39 2016 +0200

    configure: bump gtk version requirement
    
    For the new scrolled window property

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 9ea0f78..2f0b0ba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5,7 +5,7 @@ dnl ===========================================================================
 m4_define(glib_minver,                 2.49.1)
 m4_define(gnome_desktop_minver,        3.0.0)
 m4_define(pango_minver,                1.28.3)
-m4_define(gtk_minver,                  3.19.12)
+m4_define(gtk_minver,                  3.21.5)
 m4_define(xml_minver,                  2.7.8)
 m4_define(exif_minver,                 0.6.20)
 m4_define(exempi_minver,               2.1.0)