test_switch_scale_cancel failed on mako image #95

This test failed on mako image #95 with the following error:

Traceback (most recent call last):
  File "/home/phablet/autopilot/ubuntu_weather_app/tests/test_settings.py", line 182, in test_switch_scale_cancel
    units_selector = self._get_selector("TemperatureUnitsSelector")
  File "/home/phablet/autopilot/ubuntu_weather_app/tests/test_settings.py", line 143, in _get_selector
    objectName=object_name)
  File "/usr/lib/python3/dist-packages/autopilot/introspection/dbus.py", line 299, in wait_select_single
    return self.select_single(type_name, **kwargs)
  File "/usr/lib/python3/dist-packages/autopilot/introspection/dbus.py", line 244, in select_single
    instances = self._execute_query(new_query)
  File "/usr/lib/python3/dist-packages/autopilot/introspection/dbus.py", line 94, in _execute_query
    type(self)
  File "/usr/lib/python3/dist-packages/autopilot/introspection/backends.py", line 237, in execute_query_get_proxy_instances
    data = self.execute_query_get_data(query)
  File "/usr/lib/python3/dist-packages/autopilot/introspection/backends.py", line 223, in execute_query_get_data
    query.server_query_bytes()
  File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 70, in __call__
    return self._proxy_method(*args, **keywords)
  File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 145, in __call__
    **keywords)
  File "/usr/lib/python3/dist-packages/dbus/connection.py", line 651, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not
send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

It looks very much like a transient issue and I was not able to reproduce it locally, but raising it in order to keep track of it.