test_object: fix trace test
test_object: fix trace test

Change-Id: I5ebc7bbe75f24b0125871eb651c950775f11b8d4
Reviewed-on: http://gerrit.aldebaran.lan/44444
Reviewed-by: pdaouadi <fc1eb3334d3fdad315bae23aa166bc70bd434067@aldebaran-robotics.com>
Tested-by: pdaouadi <fc1eb3334d3fdad315bae23aa166bc70bd434067@aldebaran-robotics.com>

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