fixed wxListCtrl::SetItem -- changing attributes of item with attributes already set had no effect

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@8108 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/listctrl.cpp

@@ -632,6 +632,7 @@ bool wxListCtrl::SetItem(wxListItem& info)
     // check whether it has any custom attributes
     if ( info.HasAttributes() )
     {
+        m_attrs.Delete(item.iItem); // remove existing attributes
         m_attrs.Put(item.iItem, (wxObject *)new wxListItemAttr(*info.GetAttributes()));
 
         m_hasAnyAttr = TRUE;