don't crash if a dbus scan fails at startup

If a service does not implement the required interface(s)
to be scanned, instead of crashing, rather just ignore that
service.

dbus_mqtt.py

@@ -214,7 +214,10 @@ def __init__(self, mqtt_server=None, ca_cert=None, user=None, passwd=None, dbus_
  for service in services:
  if service.startswith('com.victronenergy.'):
  self._service_ids[self._dbus_conn.get_name_owner(service)] = service
- self._scan_dbus_service(service)
+ try:
+ self._scan_dbus_service(service)
+ except:
+ logging.exception("_scan_dbus_service")
 
  self._keep_alive_interval = keep_alive_interval
  MqttGObjectBridge.__init__(self, mqtt_server, "ve-dbus-mqtt-py", ca_cert, user, passwd, debug)