Qt4: make sure Item can be scrolled to visible even in treeview

Change visible-root to currents parent so it's visible. Not sure if
it's best way to do it, but atleast you don't get lost why isn't current
item visible on playlist in tree-mode.

modules/gui/qt4/components/playlist/standardpanel.cpp

@@ -159,6 +159,7 @@ void StandardPLPanel::gotoPlayingItem()
 void StandardPLPanel::handleExpansion( const QModelIndex& index )
 {
     assert( currentView );
+    browseInto( index.parent() );
     currentView->scrollTo( index );
 }