SessionService: Fix segmentation fault on close
SessionService: Fix segmentation fault on close

Fixes #22032

Change-Id: Ic46c948c5cfdcd92aaa4883fc059dbadba5b769e
Reviewed-on: http://gerrit.aldebaran.lan/39810
Reviewed-by: pdaouadi <fc1eb3334d3fdad315bae23aa166bc70bd434067@aldebaran-robotics.com>
Tested-by: pdaouadi <fc1eb3334d3fdad315bae23aa166bc70bd434067@aldebaran-robotics.com>

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