Revert "[rbrowser] Make fCleanupHandle a pointer to TObject"

This reverts commit 980c757.

Author: vepadulano

gui/browserv7/inc/ROOT/RBrowserData.hxx

@@ -48,7 +48,7 @@ class RBrowserData {
    std::vector<const Browsable::RItem *> fLastSortedItems;   ///<! sorted child items, used in requests
    std::string fLastSortMethod;                          ///<! last sort method
    bool fLastSortReverse{false};                         ///<! last request reverse order
-   std::unique_ptr<TObject> fCleanupHandle;              ///<! cleanup handle for RecursiveRemove
+   std::unique_ptr<RBrowserDataCleanup> fCleanupHandle;  ///<! cleanup handle for RecursiveRemove
 
    void ResetLastRequestData(bool with_element);