CardDatabaseDisplayModel: sort cards by search term only when the current sort column is NameColumn

When the list os sorted using another column, you don’t  need to
compare that column’s value with the searched term

cockatrice/src/carddatabasemodel.cpp

@@ -125,7 +125,7 @@ bool CardDatabaseDisplayModel::lessThan(const QModelIndex &left, const QModelInd
     QString leftString = sourceModel()->data(left).toString();
     QString rightString = sourceModel()->data(right).toString();
 
-    if (!cardName.isEmpty())
+    if (!cardName.isEmpty() && left.column() == CardDatabaseModel::NameColumn)
     {
         if (leftString.compare(cardName, Qt::CaseInsensitive) == 0) {// exact match should be at top
             return true;