SVGHMI: Fix update of HMI tree in UI when loading from XML at start. Removed some dead code left after split of svghmi.py into svghmi.py+ui.py.
<?xml version='1.0' encoding='utf-8'?>
<SVGHMI xmlns:xsd="http://www.w3.org/2001/XMLSchema" OnWatchdog="echo Watchdog for {name} !" OnStart="chromium http://127.0.0.1:{port}/{name}" OnStop="echo Closing {name}" WatchdogInitial="10" WatchdogInterval="5"/>