Avoid needless ListenerList temporary

Change-Id: I0670a013136c8d8d7e7fb5caca54812f4fa490e4
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/88422
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

sd/source/ui/framework/configuration/ConfigurationControllerBroadcaster.cxx

@@ -46,7 +46,7 @@ void ConfigurationControllerBroadcaster::AddListener(
             mxConfigurationController,
             0);
 
-    maListenerMap.try_emplace(rsEventType, ListenerList());
+    maListenerMap.try_emplace(rsEventType);
 
     ListenerDescriptor aDescriptor;
     aDescriptor.mxListener = rxListener;