[perl-Gtk2] Add missing version guards

[Torsten Schönfeld <tsch src gnome org>]

commit 0479cad395ca2f4ce62564e5d4d46bfc3def9e33
Author: Torsten Schönfeld <kaffeetisch gmx de>
Date:   Sat Oct 30 15:53:03 2010 +0200

    Add missing version guards

 xs/GdkWindow.xs |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/xs/GdkWindow.xs b/xs/GdkWindow.xs
index 22a2ec9..756cfe7 100644
--- a/xs/GdkWindow.xs
+++ b/xs/GdkWindow.xs
@@ -195,8 +195,12 @@ MODULE = Gtk2::Gdk::Window	PACKAGE = Gtk2::Gdk::Window	PREFIX = gdk_window_
 
 
 BOOT:
-	gperl_signal_set_marshaller_for (GDK_TYPE_WINDOW, "from-embedder", gtk2perl_offscreen_coord_translate_marshal);
-	gperl_signal_set_marshaller_for (GDK_TYPE_WINDOW, "to-embedder", gtk2perl_offscreen_coord_translate_marshal);
+#if GTK_CHECK_VERSION (2, 18, 0)
+	gperl_signal_set_marshaller_for (GDK_TYPE_WINDOW, "from-embedder",
+		gtk2perl_offscreen_coord_translate_marshal);
+	gperl_signal_set_marshaller_for (GDK_TYPE_WINDOW, "to-embedder",
+		gtk2perl_offscreen_coord_translate_marshal);
+#endif
 
 =for position post_signals