Add explicit keyword

kaddressbook/plugins/mergelib/job/mergecontacts.h

@@ -14,7 +14,7 @@ namespace KABMergeContacts
 class MergeContacts
 {
 public:
-    MergeContacts(const Akonadi::Item::List &items = Akonadi::Item::List());
+    explicit MergeContacts(const Akonadi::Item::List &items = Akonadi::Item::List());
     ~MergeContacts();
 
     enum ConflictInformation {

kaddressbook/plugins/mergelib/manualmerge/mergecontactwidgetlist.h

@@ -15,7 +15,7 @@ namespace KABMergeContacts
 class MergeContactWidgetListItem : public QListWidgetItem
 {
 public:
-    MergeContactWidgetListItem(const Akonadi::Item &item, QListWidget *parent = nullptr);
+    explicit MergeContactWidgetListItem(const Akonadi::Item &item, QListWidget *parent = nullptr);
     Q_REQUIRED_RESULT Akonadi::Item item() const;
 
 private: