Fix using 'import qi' from a working dir different that bin/

Change-Id: I07b7f2efb851c2a21f9d3ce6eca5b4160533f568
Reviewed-on: http://gerrit.aldebaran.lan/45715
Reviewed-by: dmerejkowsky <dmerejkowsky@aldebaran-robotics.com>
Tested-by: dmerejkowsky <dmerejkowsky@aldebaran-robotics.com>