Fix compilation

Hide a symbol if we're not compiling with Wayland compositor support.

clutter/clutter-backend.c

@@ -269,11 +269,13 @@ clutter_backend_real_create_context (ClutterBackend  *backend,
   if (backend->cogl_renderer == NULL)
     goto error;
 
+#ifdef HAVE_CLUTTER_WAYLAND_COMPOSITOR
   /* If the application is trying to act as a Wayland compositor then
      it needs to have an EGL-based renderer backend */
   if (_wayland_compositor_display)
     cogl_renderer_add_constraint (backend->cogl_renderer,
                                   COGL_RENDERER_CONSTRAINT_USES_EGL);
+#endif
 
   CLUTTER_NOTE (BACKEND, "Connecting the renderer");
   if (!cogl_renderer_connect (backend->cogl_renderer, &internal_error))