message: setError: clear the buffer before setting an error
message: setError: clear the buffer before setting an error

Change-Id: I384dd74f6da380674bf1df90691b2fdf4f0792ae
Reviewed-on: http://gerrit.aldebaran.lan/63797
Reviewed-by: vpaleologue <cb19838a79eb484e12a6960acfbf7c16dfdb80d9@aldebaran-robotics.com>
Reviewed-by: pdaouadi <fc1eb3334d3fdad315bae23aa166bc70bd434067@aldebaran-robotics.com>
Tested-by: pdaouadi <fc1eb3334d3fdad315bae23aa166bc70bd434067@aldebaran-robotics.com>

aldebaran/libqi,aldebaran/libqi,aldebaran/libqi