beremiz

IDE+Runtime: fix exception when reconnecting with non-empty trace/force list.

Sometimes, remote call to SetTraceVariableList returned None just after reconnecting:
- changed caller to accept None (in case of connection problem)
- changer SetTraceVariable list to return 4 (DEBUG_SUSPENDED) if debug is suspended
#!/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 *