Fix thread-safeness of pair initialization.
Fix thread-safeness of pair initialization.

Change-Id: I400bcf2b0e52a5535460646cc6067e6ea4de044a
Reviewed-on: http://gerrit.aldebaran.lan/36092
Reviewed-by: pdaouadi <fc1eb3334d3fdad315bae23aa166bc70bd434067@aldebaran-robotics.com>
Reviewed-by: mnottale <e3ccf1b6558404e921a21fa09cebb1153b50ec36@aldebaran-robotics.com>
Tested-by: mnottale <e3ccf1b6558404e921a21fa09cebb1153b50ec36@aldebaran-robotics.com>

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