Fix #8617: QI_COMPILER_WARNING does nothing by default

Change-Id: I65209752941dcc461b74d2dc62c3b0ae1438a56a
Reviewed-on: http://gerrit.aldebaran.lan:8080/10374
Reviewed-by: dmerejkowsky <dmerejkowsky@aldebaran-robotics.com>
Reviewed-by: llec <llec@aldebaran-robotics.com>
Tested-by: hcuche <hcuche@aldebaran-robotics.com>