SVGHMI: move declaration of "xmlns" javascript const so that widgets can use it.
This was broken in earlier commit, when changing initial execution order because of implementing websocket reconnect.
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This file is part of Beremiz
# Copyright (C) 2019: Edouard TISSERANT
#
# See COPYING file for copyrights details.
from __future__ import absolute_import
from svghmi.svghmi import *