Revert "Build only 2 changes at a time"

The NUC is back online and from tomorrow we should have
+2 more nodes.

This reverts commit f4bfa8bee3869411f95317201c1785174a5ab919.

Reason for revert: We have more horsepower now

Change-Id: I04233990b33e12d2a3e39596a913a7110a1b92f4
diff --git a/jenkins/gerrit-verifier-flow.groovy b/jenkins/gerrit-verifier-flow.groovy
index 20c12b9..4779d63 100644
--- a/jenkins/gerrit-verifier-flow.groovy
+++ b/jenkins/gerrit-verifier-flow.groovy
@@ -33,7 +33,7 @@
   static int numRetryBuilds = 3
   static int myAccountId = 1022687
   static int waitForResultTimeout = 10000
-  static int maxBuilds = 2
+  static int maxBuilds = 4
   static String verifierJobName = "Gerrit-verifier-change"
 }