wizard: Prevent crash

Summary: If we get here when curpage is NULL, we'll crash later, so we should test for it.

Reviewers: zmike

Subscribers: cedric

Differential Revision: https://phab.enlightenment.org/D2789

src/modules/wizard/e_wizard.c

@@ -401,7 +401,7 @@ _e_wizard_cb_desktops_update(void *data __UNUSED__, int ev_type __UNUSED__, void
    if ((e) && (e->error))
      xdg_error = EINA_TRUE;
    got_desktops = EINA_TRUE;
-   if (_e_wizard_check_xdg())
+   if (curpage && _e_wizard_check_xdg())
      _e_wizard_next_xdg();
    return ECORE_CALLBACK_PASS_ON;
 }