Notify wxPropertyGrid about selected property only if new page was selected

wxPropertyGridManager::DoSelectPage() returns true also if new page is
the same as the current one so we have to use alternative way to check
whether we really switched to the new page.

src/propgrid/propgridiface.cpp

@@ -1175,7 +1175,9 @@ bool wxPropertyGridInterface::RestoreEditableState( const wxString& src, int res
 
     if ( selectedPage != -1 )
     {
-        if ( DoSelectPage(selectedPage) )
+        wxPropertyGridPageState* curPageState = GetPageState(-1);
+        DoSelectPage(selectedPage);
+        if ( GetPageState(-1) != curPageState )
         {
             pg->SendEvent(wxEVT_PG_SELECTED, pg->GetSelectedProperty());
         }