ctest: set VALGRIND=1 in env when running under valgrind
ctest: set VALGRIND=1 in env when running under valgrind

Change-Id: I2f520c3e89f936ce6afe36b6c15ba7d1a7fb076e
Reviewed-on: http://gerrit.aldebaran.lan:8080/4261
Reviewed-by: dmerejkowsky <1e4b13000fa8777df4cefd2fd8215187e3deb062@aldebaran-robotics.com>
Tested-by: cgestes <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>

dmerejkowsky/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,aldebaran/qibuild