log: rename category from Translator to qi.translator

Change-Id: I727cc80e4d4bdcc41cb80eca1c1bae7c7c9c298c
Reviewed-on: http://gerrit.aldebaran.lan/40117
Reviewed-by: hcuche <hcuche@aldebaran-robotics.com>
Reviewed-by: pdaouadi <pdaouadi@aldebaran-robotics.com>
Tested-by: pdaouadi <pdaouadi@aldebaran-robotics.com>
Merge commit 'refs/integration/team/hotfix/dev-187'