Fix LV2 UI lockup on show with newer juce

Signed-off-by: falkTX <falktx@falktx.com>

libs/juce-current/source/modules/juce_audio_plugin_client/LV2/juce_LV2_Wrapper.cpp

@@ -153,6 +153,8 @@ public:
         const ScopedJuceInitialiser_GUI juceInitialiser;
 
         MessageManager::getInstance()->setCurrentThreadAsMessageThread();
+
+        XWindowSystem::getInstance();
         initialised = true;
 
         MessageManager::getInstance()->runDispatchLoop();