Increase number of concurrent jobs

Change-Id: I18411107d093dd562d3b017ade3a7c815bb4e866
diff --git a/test-salt-formulas-pipeline.groovy b/test-salt-formulas-pipeline.groovy
index a475e3a..4422ca6 100644
--- a/test-salt-formulas-pipeline.groovy
+++ b/test-salt-formulas-pipeline.groovy
@@ -20,7 +20,7 @@
 try {
   parallelGroupSize = Integer.valueOf(PARALLEL_GROUP_SIZE)
 } catch (MissingPropertyException e) {
-  parallelGroupSize = 4
+  parallelGroupSize = 8
 }
 
 def defaultGitRef, defaultGitUrl