Fix isProcessRunning unit test on mac OS
Fix isProcessRunning unit test on mac OS

At some point the test work with invalid pid value.

Change-Id: Ib15add8f66950ccfdde2ccda0cb13a5ee3da6c45
Reviewed-on: http://gerrit.aldebaran.lan/72024
Tested-by: hcuche <2a0975cc082cedff4d4350e3f6ec187146151bc6@aldebaran.com>
Reviewed-by: jmonnon <8898eaf233516e520f996a244ca8a12d20f948b1@aldebaran.com>
Reviewed-by: hcuche <2a0975cc082cedff4d4350e3f6ec187146151bc6@aldebaran.com>

aldebaran/libqi,aldebaran/libqi,aldebaran/libqi