Rename settings_oslo parameter MANAGER to ENV_MANAGER

ENV_MANAGER variable will be used to activate one of
the environment managers:
ENV_MANAGER=devops - create, power on/off VM and BM nodes,
                     snapshots for libvirt VMs
ENV_MANAGER=heat   - create OpenStack heat stack
ENV_MANAGER=empty  - only for SSH to an existing environment

Change-Id: I90a59107a7fd350ecfeb821734c2dac4e351d468
diff --git a/jobs/pipelines/swarm-run-pytest.groovy b/jobs/pipelines/swarm-run-pytest.groovy
index 99231f9..994cc70 100644
--- a/jobs/pipelines/swarm-run-pytest.groovy
+++ b/jobs/pipelines/swarm-run-pytest.groovy
@@ -65,7 +65,7 @@
 
                 shared.run_sh(sources + installed + """
                     export TESTS_CONFIGS=${ENV_NAME}_salt_deployed.ini
-                    export MANAGER=devops  # use 'hardware' fixture to manage fuel-devops environment
+                    export ENV_MANAGER=devops  # use 'hardware' fixture to manage fuel-devops environment
                     export salt_master_host=\$SALT_MASTER_IP  # skip salt_deployed fixture
                     export salt_master_port=6969
                     export SALT_USER=\$SALTAPI_USER