models: pass header descriptions in CleanerTableModel constructor

For the "CleanerHeaderModel" to work, the deriving class has to
set the header descriptions. Failing to do so led to bug #4294.

To avoid that in the future force the deriving class to pass
the headers in the constructor.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

qt-models/cleanertablemodel.cpp

@@ -20,7 +20,8 @@ const QPixmap &editIcon()
 	return edit;
 }
 
-CleanerTableModel::CleanerTableModel(QObject *parent) : QAbstractTableModel(parent)
+CleanerTableModel::CleanerTableModel(QStringList headers, QObject *parent) : QAbstractTableModel(parent),
+	headers(headers)
 {
 }
 
@@ -42,8 +43,3 @@ QVariant CleanerTableModel::headerData(int section, Qt::Orientation orientation,
 	}
 	return QVariant();
 }
-
-void CleanerTableModel::setHeaderDataStrings(const QStringList &newHeaders)
-{
-	headers = newHeaders;
-}