Remove some qOverload as we remove deprecated qt5.15 signal

src/prefs/koprefsdialogcolorsandfonts.cpp

@@ -104,7 +104,7 @@ KOPrefsDialogColorsAndFonts::KOPrefsDialogColorsAndFonts(QWidget *parent, const
                                        "Select the tag you want to modify. "
                                        "You can change the selected tag's color using "
                                        "the adjacent color button."));
-    connect(mCategoryCombo, qOverload<int>(&KComboBox::activated), this, &KOPrefsDialogColorsAndFonts::updateCategoryColor);
+    connect(mCategoryCombo, &KComboBox::activated, this, &KOPrefsDialogColorsAndFonts::updateCategoryColor);
     categoryLayout->addWidget(mCategoryCombo, 1, 0);
 
     mCategoryButton = new KColorButton(categoryGroup);

src/prefs/koprefsdialogtime.cpp

@@ -201,7 +201,7 @@ KOPrefsDialogTime::KOPrefsDialogTime(QWidget *parent, const QVariantList &args)
     mReminderUnitsCombo = new KComboBox(defaultPage);
     mReminderUnitsCombo->setToolTip(CalendarSupport::KCalPrefs::instance()->reminderTimeUnitsItem()->toolTip());
     mReminderUnitsCombo->setWhatsThis(CalendarSupport::KCalPrefs::instance()->reminderTimeUnitsItem()->whatsThis());
-    connect(mReminderUnitsCombo, qOverload<int>(&KComboBox::activated), this, &KOPrefsDialogTime::slotWidChanged);
+    connect(mReminderUnitsCombo, &KComboBox::activated, this, &KOPrefsDialogTime::slotWidChanged);
     mReminderUnitsCombo->addItem(i18nc("@item:inlistbox reminder units in minutes", "minute(s)"));
     mReminderUnitsCombo->addItem(i18nc("@item:inlistbox reminder time units in hours", "hour(s)"));
     mReminderUnitsCombo->addItem(i18nc("@item:inlistbox reminder time units in days", "day(s)"));

src/prefs/kprefsdialog.cpp

@@ -465,7 +465,7 @@ KPrefsWidCombo::KPrefsWidCombo(KConfigSkeleton::ItemEnum *item, QWidget *parent)
 {
     mLabel = new QLabel(mItem->label(), parent);
     mCombo = new KComboBox(parent);
-    connect(mCombo, qOverload<int>(&KComboBox::activated), this, &KPrefsWidCombo::changed);
+    connect(mCombo, &KComboBox::activated, this, &KPrefsWidCombo::changed);
     mLabel->setBuddy(mCombo);
     QString toolTip = mItem->toolTip();
     if (!toolTip.isEmpty()) {