Actually update the supported interface status

With this Waves VST3 plugins now work. But was it worth it?

src/plugin/bridges/vst3-impls/plugin-proxy.cpp

@@ -1057,7 +1057,7 @@ tresult PLUGIN_API Vst3PluginProxyImpl::initialize(FUnknown* context) {
         host_application = host_context;
         plug_interface_support = host_context;
 
-        const InitializeResponse response =
+        InitializeResponse response =
             bridge.send_message(Vst3PluginProxy::Initialize{
                 .instance_id = instance_id(),
                 .host_context_args = Vst3HostContextProxy::ConstructArgs(
@@ -1066,7 +1066,8 @@ tresult PLUGIN_API Vst3PluginProxyImpl::initialize(FUnknown* context) {
         // HACK: For some reason, Waves plugins will only allow querying the
         //       `IEditController` interface after this point, so we need to
         //       update the list of interfaces we support for this object.
-        arguments = response.updated_plugin_interfaces;
+        update_supported_interfaces(
+            std::move(response.updated_plugin_interfaces));
 
         return response.result;
     } else {