python: isinstance: Fix behavior for case (a,b)=(notobject,object).
python: isinstance: Fix behavior for case (a,b)=(notobject,object).

Change-Id: Ia1d047e80e0ea9bbd13962424895dec012e0ab78
Reviewed-on: http://gerrit.aldebaran.lan/28205
Reviewed-by: cgestes <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>
Tested-by: cgestes <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>

aldebaran/libqi,aldebaran/libqi,vbarbaresi/libqi,aldebaran/libqi,bsautron/libqi