Fix PeriodicTask comment
Fix PeriodicTask comment

Change-Id: I9718271a9a3aecff75c2414cd9295f8832fea3cf
Reviewed-on: http://gerrit.aldebaran.lan/35677
Reviewed-by: mnottale <e3ccf1b6558404e921a21fa09cebb1153b50ec36@aldebaran-robotics.com>
Reviewed-by: pdaouadi <fc1eb3334d3fdad315bae23aa166bc70bd434067@aldebaran-robotics.com>
Tested-by: pdaouadi <fc1eb3334d3fdad315bae23aa166bc70bd434067@aldebaran-robotics.com>

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