tests_elasticsearch: fix updated_on() tests
tests_elasticsearch: fix updated_on() tests

iksaif/biggraphite,Thib17/biggraphite,Thib17/biggraphite,criteo/biggraphite,iksaif/biggraphite,criteo/biggraphite,Thib17/biggraphite,iksaif/biggraphite,Thib17/biggraphite,criteo/biggraphite,iksaif/biggraphite,criteo/biggraphite