fix args in nova:compute state apply

Change-Id: I7d5c52969ac7d6e17e0b09e5eb649642185a2c18
diff --git a/lab-pipeline.groovy b/lab-pipeline.groovy
index 4235213..9bc3fac 100644
--- a/lab-pipeline.groovy
+++ b/lab-pipeline.groovy
@@ -365,7 +365,7 @@
                     //orchestrate.installOpenstackMkCompute(saltMaster, physical)
                     // Configure compute nodes
                     retry(2) {
-                        salt.runSaltProcessStep(saltMaster, 'I@nova:compute', 'state.apply', null, true)
+                        salt.runSaltProcessStep(saltMaster, 'I@nova:compute', 'state.apply', [], null, true)
                     }
 
                     // Provision opencontrail virtual routers