Let's not use too advanced C++11 features

src/model/danboorutagmodel.h

@@ -34,7 +34,7 @@ Q_OBJECT
 
 public:
     explicit DanbooruTagModel(QObject* parent=0);
-    ~DanbooruTagModel() = default;
+    ~DanbooruTagModel();
     int rowCount(const QModelIndex &parent = QModelIndex()) const Q_DECL_OVERRIDE;
     QVariant data(const QModelIndex &index, int role) const Q_DECL_OVERRIDE;
     void clear();