[gtkmm/gtkmm-3-24] configure.ac: Require giomm-2.4 >= 2.54.0

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 5bc9ec995b3beebaa298d1e7cb3ce387fcd50bce
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Fri Sep 7 10:23:00 2018 +0200

    configure.ac: Require giomm-2.4 >= 2.54.0
    
    Glibmm 2.54.0 introduces useful features in gmmproc:
    - Accept curly braces in default values in _WRAP macros.
    - Add new element types for the docs_override.xml files:
      substitute_type_name and substitute_enumerator_name.
    And more.

 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/configure.ac b/configure.ac
index 8374b0e0..465b9a73 100644
--- a/configure.ac
+++ b/configure.ac
@@ -95,7 +95,7 @@ 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 >= 2.49.1 pangomm-1.4 >= 2.38.2 gtk+-3.0 >= 3.22.0 cairomm-1.0 >= 
1.12.0 gdk-pixbuf-2.0 >= 2.35.5'])
+AC_SUBST([GDKMM_MODULES], ['giomm-2.4 >= 2.54.0 pangomm-1.4 >= 2.38.2 gtk+-3.0 >= 3.22.0 cairomm-1.0 >= 
1.12.0 gdk-pixbuf-2.0 >= 2.35.5'])
 
 AS_IF([test "x$gtkmm_host_windows" = xyes],
       [GTKMM_MODULES=$GDKMM_MODULES],