Gatling tests: bump Gerrit to v3.4.0-rc0

Change-Id: I4fda240aa1bd6461622c50bbda7cd8bc69dac957
diff --git a/jenkins/gatling-test-pipeline.groovy b/jenkins/gatling-test-pipeline.groovy
index 270f934..e092dc4 100644
--- a/jenkins/gatling-test-pipeline.groovy
+++ b/jenkins/gatling-test-pipeline.groovy
@@ -9,8 +9,8 @@
             string(name: 'AWS_PREFIX', defaultValue:"jenkins", description: 'A string to prefix stacks and resources with')
             string(name: 'AWS_REGION', defaultValue:"us-east-1", description: 'Which region to deploy to')
 
-            string(name: 'GERRIT_VERSION', defaultValue:"3.3", description: 'The gerrit version under test')
-            string(name: 'GERRIT_PATCH', defaultValue:"2", description: 'The gerrit version patch under test')
+            string(name: 'GERRIT_VERSION', defaultValue:"3.4", description: 'The gerrit version under test')
+            string(name: 'GERRIT_PATCH', defaultValue:"0-rc0", description: 'The gerrit version patch under test')
 
             string(name: 'HOSTED_ZONE_NAME', defaultValue: "gerritforgeaws.com", description: 'Name of the hosted zone')
             string(name: 'CLUSTER_INSTANCE_TYPE', defaultValue: 'm4.xlarge', description:'The EC2 instance Type used to run the cluster')