Show log when message is empty

Change-Id: I98caf685fc16b1267e9d5571783a2fdb2576308d
Reviewed-on: http://gerrit.aldebaran.lan:8080/17563
Reviewed-by: hcuche <hcuche@aldebaran-robotics.com>
Reviewed-by: ncornu <ncornu@aldebaran-robotics.com>
Tested-by: gerrit
Reviewed-by: cgestes <gestes@aldebaran-robotics.com>
QI_GEN_RANGE: New. QI_GEN with specified max value.

Change-Id: Iad1a3b7624e7eaa5f296c3b2845c180eefe509c8