[gcalctool] Remove deprecated GTK_WIDGET_TOPLEVEL, bump required GTK to 2.18

[Robin Sonefors <rsonefors src gnome org>]

commit e5ffafc77ac0e1ddc72d802bd411561eaed532b8
Author: Robin Sonefors <ozamosi flukkost nu>
Date:   Wed Jan 6 23:43:30 2010 +0100

    Remove deprecated GTK_WIDGET_TOPLEVEL, bump required GTK to 2.18

 configure.in |    2 +-
 src/gtk.c    |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/configure.in b/configure.in
index 5e74322..0d946d7 100644
--- a/configure.in
+++ b/configure.in
@@ -18,7 +18,7 @@ dnl ###########################################################################
 dnl Dependencies
 dnl ###########################################################################
 
-GTK_REQUIRED=2.17.5
+GTK_REQUIRED=2.18
 GCONF_REQUIRED=1.1.9
 
 PKG_CHECK_MODULES(GCALCTOOL, [
diff --git a/src/gtk.c b/src/gtk.c
index 8a805f3..76b0cc4 100644
--- a/src/gtk.c
+++ b/src/gtk.c
@@ -680,7 +680,7 @@ finc_activate_cb(GtkWidget *widget) {
     if (finc_dialog_fields[dialog][field+1] == NULL) {
         GtkWidget *dialog_widget;
         dialog_widget = gtk_widget_get_toplevel(widget);
-        if (GTK_WIDGET_TOPLEVEL (dialog_widget)) {
+        if (gtk_widget_is_toplevel (dialog_widget)) {
             gtk_dialog_response(GTK_DIALOG(dialog_widget),
                                 GTK_RESPONSE_OK);
             return;