Attempting to fix jetty-9.2.x build

Jenkinsfile

@@ -1,9 +1,10 @@
 #!groovy
 
-node {
+node("linux") {
   // System Dependent Locations
+  def jdk = 'jdk7'
   def mvntool = tool name: 'maven3.5', type: 'hudson.tasks.Maven$MavenInstallation'
-  def jdktool = tool name: 'jdk7', type: 'hudson.model.JDK'
+  def jdktool = tool name: $jdk, type: 'hudson.model.JDK'
   def mvnName = 'maven3.5'
   def localRepo = "${env.JENKINS_HOME}/${env.EXECUTOR_NUMBER}" // ".repository" //
   def settingsName = 'oss-settings.xml'