qi.messaging: Fixes compilation warning in socket.
qi.messaging: Fixes compilation warning in socket.

The variable `io` is not used.

Change-Id: I03d0a14c48f47afebcef314d233af249c9de04df
Reviewed-on: http://gerrit.aldebaran.lan/94712
Reviewed-by: vpaleologue <cb19838a79eb484e12a6960acfbf7c16dfdb80d9@aldebaran-robotics.com>
Reviewed-by: vincent.palancher <f8ff75e1c61314c499fafa8de0d9e004e87e66b0@external.softbankrobotics.com>
Reviewed-by: jmonnon <8898eaf233516e520f996a244ca8a12d20f948b1@aldebaran.com>
Tested-by: vpaleologue <cb19838a79eb484e12a6960acfbf7c16dfdb80d9@aldebaran-robotics.com>

aldebaran/libqi,aldebaran/libqi,aldebaran/libqi