$NetBSD$

Make dbus optional.

--- unix/plugins/DBusPlugin/config.cmake.orig	2009-08-26 18:38:47.000000000 +0000
+++ unix/plugins/DBusPlugin/config.cmake
@@ -1 +1,7 @@
 PLUGIN_REQUIRE_PACKAGE (DBUS1 dbus-1)
+
+CHECK_LIBRARY_EXISTS (dbus-1 dbus_bus_get "" HAVE_DBUS)
+IF (NOT HAVE_DBUS)
+  PLUGIN_DISABLE ()
+ENDIF ()
+
