switch gating-pipeline to virtual slaves

Change-Id: I3179424c0453b06d28fff5c631e22ea997989264
diff --git a/gating-pipeline.groovy b/gating-pipeline.groovy
index d449cd8..e1c80f0 100644
--- a/gating-pipeline.groovy
+++ b/gating-pipeline.groovy
@@ -10,7 +10,7 @@
 def gerrit = new com.mirantis.mk.Gerrit()
 def ssh = new com.mirantis.mk.Ssh()
 
-slaveNode = env.SLAVE_NODE ?: 'docker'
+slaveNode = env.SLAVE_NODE ?: 'virtual'
 giveVerify = false
 
 @NonCPS