added functions to remove the abstract class error

src/modules/launcher/Wox.Launcher/dllmain.cpp

@@ -254,6 +254,11 @@ public:
     }
     return 0;
   }
+
+  /* Register helper class to handle system menu items related actions. */
+  virtual void register_system_menu_helper(PowertoySystemMenuIface* helper) {}
+  /* Handle action on system menu item. */
+  virtual void signal_system_menu_action(const wchar_t* name) {}
 };
 
 // Load the settings file.