[regexxer/murrayc-update] Require even newer gtkmm that uses C++11.

[Murray Cumming <murrayc src gnome org>]

commit 28ae2511303cbd6f1f0b6b6aebc834d4f989bd11
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Mar 1 09:32:59 2016 +0100

    Require even newer gtkmm that uses C++11.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 65d4d60..b84a51a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -38,7 +38,7 @@ AM_GNU_GETTEXT_VERSION([0.11])
 AM_GLIB_GNU_GETTEXT
 
 PKG_CHECK_MODULES([REGEXXER_MODULES],
-                  [gtkmm-3.0 >= 3.12 glibmm-2.4 >= 2.27.94
+                  [gtkmm-3.0 >= 3.18 glibmm-2.4 >= 2.27.94
                   gtksourceviewmm-3.0 >= 2.91.5])
 
 DK_PKG_PATH_PROG([GDK_PIXBUF_CSOURCE], [gdk-pixbuf-2.0], [gdk-pixbuf-csource])