Update comment for new Qt 5.10 API

Differential Revision: https://phabricator.kde.org/D9099

src/krecursivefilterproxymodel.h

@@ -34,7 +34,7 @@ class KRecursiveFilterProxyModelPrivate;
   Until Qt 5.10, QSortFilterProxyModel did not recurse when invoking a filtering stage, so that
   if a particular row is filtered out, its children are not even checked to see if they match the filter.
 
-  If you can depend on Qt >= 5.10, then just use QSortFilterProxyModel::setRecursiveFiltering(true),
+  If you can depend on Qt >= 5.10, then just use QSortFilterProxyModel::setRecursiveFilteringEnabled(true),
   and you don't need to use KRecursiveFilterProxyModel.
 
   For example, given a source model: