Avoid IAudioProcessor::isActive() on GUI thread

I haven't seen this cause any issues this way, and I could imagine that
this could cause some hangs when initializing a second instance of a
plugin while you're interacting with the GUI of the first instance.

src/wine-host/bridges/vst3.cpp

@@ -1303,10 +1303,7 @@ size_t Vst3Bridge::register_object_instance(
                         //       handled from the same thread to prevent
                         //       deadlocks caused by mutually recursive function
                         //       calls.
-                        // TODO: Check if this causes any issues when activating
-                        //       plugins while simultaneously resizing another
-                        //       instance of the same plugin
-                        return do_mutual_recursion_on_gui_thread<tresult>(
+                        return do_mutual_recursion_on_off_thread<tresult>(
                             [&]() {
                                 return object_instances[request.instance_id]
                                     .component->setActive(request.state);