Fixed an unused variable warning in the VST3 wrapper

modules/juce_audio_plugin_client/VST3/juce_VST3_Wrapper.cpp

@@ -1338,6 +1338,7 @@ public:
         short configs[][2] = { JucePlugin_PreferredChannelConfigurations };
         const int numConfigs = sizeof (configs) / sizeof (short[2]);
 
+        ignoreUnused (numConfigs);
         jassert (numConfigs > 0 && (configs[0][0] > 0 || configs[0][1] > 0));
 
         pluginInstance->setPlayConfigDetails (configs[0][0], configs[0][1], 44100.0, 1024);