Signal: fix typo in comment
Signal: fix typo in comment

Change-Id: If3d7f4afb7586e908d8eadaea0955d366f472cfb
Reviewed-on: http://gerrit.aldebaran.lan/74517
Reviewed-by: jmonnon <8898eaf233516e520f996a244ca8a12d20f948b1@aldebaran.com>
Tested-by: vpaleologue <cb19838a79eb484e12a6960acfbf7c16dfdb80d9@aldebaran-robotics.com>

aldebaran/libqi,aldebaran/libqi,aldebaran/libqi