[gtkmm] Require glibmm 2.48.0

[Murray Cumming <murrayc src gnome org>]

commit a671d1cb3a04973f47d2bb451620875f319dbfe8
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Mar 28 12:17:33 2016 +0200

    Require glibmm 2.48.0

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index ae4dbfc..6ef8771 100644
--- a/configure.ac
+++ b/configure.ac
@@ -93,7 +93,7 @@ AS_IF([test "x$enable_static" = xyes],
 # gdkmm really does need GTK+, because part of Gdk::DragContext is in GTK+.
 # The extra cairomm-1.0 check is because gdkmm requires a newer cairomm than pangomm requires.
 # The extra gdk-pixbuf-2.0 check is because gdkmm requires a newer gdk-pixbuf than gtk+-3.0 requires.
-AC_SUBST([GDKMM_MODULES], ['giomm-2.4 >= 2.47.3.1 pangomm-1.4 >= 2.38.2 gtk+-3.0 >= 3.20.0 cairomm-1.0 >= 
1.12.0 gdk-pixbuf-2.0 >= 2.26.0'])
+AC_SUBST([GDKMM_MODULES], ['giomm-2.4 >= 2.48.0 pangomm-1.4 >= 2.38.2 gtk+-3.0 >= 3.20.0 cairomm-1.0 >= 
1.12.0 gdk-pixbuf-2.0 >= 2.26.0'])
 
 AS_IF([test "x$gtkmm_host_windows" = xyes],
       [GTKMM_MODULES=$GDKMM_MODULES],