[fuel-qa] Doc string of 'information_at_graphs_handler' test incorrectly describes few its steps

[Artem Panchenko]

There are 2 steps in the docstring of system test 'information_at_graphs_handler' which are not aligned with actual actions:

https://github.com/openstack/fuel-qa/blob/b99229450555073c2fe21cd50a463ded01b396cc/fuelweb_test/tests/tests_custom_graph/test_custom_graph.py#L820-L821

According to the doc string (it's also uploaded to TestRail) the tests adds new graphs to 'release', but in the code we update 'environment' data:

https://github.com/openstack/fuel-qa/blob/b99229450555073c2fe21cd50a463ded01b396cc/fuelweb_test/tests/tests_custom_graph/test_custom_graph.py#L862-L866
https://github.com/openstack/fuel-qa/blob/b99229450555073c2fe21cd50a463ded01b396cc/fuelweb_test/tests/tests_custom_graph/test_custom_graph.py#L883-L888