Do not fail while importing dbus.gobject_service from gi-less activity

[alsroot]

For some reason, dbus-python package (python-dbus-1.0.0-1ubuntu1 from Ubuntu-12.04) uses gi in dbus.gobject_service module (but generally it is gi-less). It breaks activities that are not gi based but uses dbus.gobject_service module.

[alsroot]

The  http://git.sugarlabs.org/desktop/sugar-toolkit/commit/cebf8f5c7d42f66dc3f1c6eb79c558a20083a676 commit load original, gi-less, module at the start. So, if activity will try to load this method afterwards, it will get already loaded one that came from sugar-toolkit.

[alsroot]

 http://git.sugarlabs.org/desktop/sugar-toolkit/commit/d66f484e1a1032270eadc03eee6a387e10fd3c31

[AlanJAS]

This problem also breaks activities in my sugar-emulator 0.90.

See this ticket:

 https://bugs.freedesktop.org/show_bug.cgi?id=48904