Coverity: repair previous commit

src/libcalamaresui/utils/qjsonmodel.h

@@ -17,6 +17,7 @@ class QJsonModel : public QAbstractItemModel
     Q_OBJECT
 public:
     explicit QJsonModel(QObject *parent = 0);
+    ~QJsonModel();
     bool load(const QString& fileName);
     bool load(QIODevice * device);
     bool loadJson(const QByteArray& json);