Use new api

src/kontactplugin/summary/kcmkontactsummary.cpp

@@ -37,7 +37,7 @@
 
 #include <QLabel>
 #include <QVBoxLayout>
-
+#include <kconfigwidgets_version.h>
 extern "C"
 {
 Q_DECL_EXPORT KCModule *create_kontactsummary(QWidget *parent, const char *)
@@ -109,9 +109,13 @@ KCMKontactSummary::KCMKontactSummary(QWidget *parent)
     layout->setStretchFactor(mPluginView, 1);
 
     load();
+#if KCONFIGWIDGETS_VERSION < QT_VERSION_CHECK(5, 64, 0)
     connect(mPluginView, &QTreeWidget::itemChanged,
             this, qOverload<>(&KCMKontactSummary::changed));
-
+#else
+    connect(mPluginView, &QTreeWidget::itemChanged,
+            this, &KCMKontactSummary::markAsChanged);
+#endif
     KAboutData *about = new KAboutData(QStringLiteral("kontactsummary"),
                                        i18n("kontactsummary"),
                                        QString(),