Windows: Fix a compile error when JUCE_DLL_BUILD=1

modules/juce_events/interprocess/juce_NetworkServiceDiscovery.h

@@ -120,6 +120,8 @@ struct NetworkServiceDiscovery
         void handleMessage (const XmlElement&);
         void handleMessage (const Service&);
         void removeTimedOutServices();
+
+        JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AvailableServiceList)
     };
 };