Revert "don't canFetchMore on our own"

This reverts commit b9af3706e7.

As explained MKleusberg, this might be needed, and this practise
is also used by Qt itself.

src/sqlitetablemodel.cpp

@@ -130,6 +130,10 @@ QVariant SqliteTableModel::data(const QModelIndex &index, int role) const
 
     if (role == Qt::DisplayRole)
     {
+        // If this row is not in the cache yet get it first
+        while(index.row() >= m_data.size() && canFetchMore())
+            const_cast<SqliteTableModel*>(this)->fetchMore();   // Nothing evil to see here, move along
+
         return m_data.at(index.row()).at(index.column());
     } else {
         return QVariant();