[glom] configure.ac: Avoid deprecated libsigc++ API.

[Murray Cumming <murrayc src gnome org>]

commit df4b2cab67c5c36e63e611760a72dba45549f69f
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Jul 26 13:15:54 2013 +0200

    configure.ac: Avoid deprecated libsigc++ API.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 939fb28..e592549 100644
--- a/configure.ac
+++ b/configure.ac
@@ -216,7 +216,7 @@ AC_LANG([C++])
 MM_ARG_ENABLE_WARNINGS([GLOM_WXXFLAGS],
                        [-Wall],
                        [-Wall -Wextra -Wno-missing-field-initializers -DGSEAL_ENABLE],
-                       [G GDK GDK_PIXBUF GTK GLIBMM GDKMM CAIROMM PANGOMM GTKMM])
+                       [G GDK GDK_PIXBUF GTK GLIBMM GDKMM CAIROMM PANGOMM GTKMM SIGCXX])
 
 AC_CHECK_FUNCS([strptime])