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

{
    "ID": "wamptest", 
    "active": true, 
    "protocolOptions": {
        "autoPingInterval": 60, 
        "autoPingTimeout": 20
    }, 
    "realm": "Automation", 
    "url": "ws://127.0.0.1:8888"
}