Upgrade on bitnami Jenkins AMI.
#!/usr/bin/env bash
sudo /opt/bitnami/ctlscript.sh stop
sudo cp /opt/bitnami/apache-tomcat/webapps/jenkins/jenkins.war /opt/bitnami/apps/jenkins/jenkins.war.bak
wget http://mirrors.jenkins-ci.org/war/latest/jenkins.war
sudo mv jenkins.war /opt/bitnami/apache-tomcat/webapps/jenkins
sudo chown tomcat:tomcat /opt/bitnami/apache-tomcat/webapps/jenkins/jenkins.war
sudo /opt/bitnami/ctlscript.sh restart