PROD-35900 Conditional deployment of the empty node

Change-Id: If8dec13efbb862d14f6d8ff0108ee18b9795234e
diff --git a/jobs/pipelines/swarm-bootstrap-salt-cluster-heat.groovy b/jobs/pipelines/swarm-bootstrap-salt-cluster-heat.groovy
index ba52899..7ae510e 100644
--- a/jobs/pipelines/swarm-bootstrap-salt-cluster-heat.groovy
+++ b/jobs/pipelines/swarm-bootstrap-salt-cluster-heat.groovy
@@ -30,6 +30,7 @@
  *   JENKINS_PIPELINE_BRANCH       Should be set in release/proposed/2019.2.0 when we test non-released version
  *   UPDATE_VERSION                Version of update to deploy
  *   LAB_PARAM_DEFAULTS            Filename placed in tcp_tests/templates/_heat_environments, with default parameters for the heat template
+ *   DEPLOY_EMPTY_NODE             Add extra node to heat stack. Node without a role and with salt-minion
  *
  *   CREATE_JENKINS_NODE_CREDENTIALS   Jenkins username and password with rights to add/delete Jenkins agents
  */
@@ -162,6 +163,7 @@
                             export ENV_NAME=${ENV_NAME}
                             export LAB_CONFIG_NAME=${LAB_CONFIG_NAME}
                             export LAB_PARAM_DEFAULTS=${LAB_PARAM_DEFAULTS}
+                            export DEPLOY_EMPTY_NODE=${DEPLOY_EMPTY_NODE}
                             export LOG_NAME=swarm_test_create_environment.log
                             py.test --cache-clear -vvv -s -p no:django -p no:ipdb --junit-xml=deploy_hardware.xml -k \${TEST_GROUP}
                         """)