Fix Jenkin's $JENKINS_HOME/war/ content, since $JENKINS_HOME/war/WEB-INF/slave.jar is being used by slaves (scp fetching)

Once we started Jenkins w/ a method where the jenkins.war file got inflated into $JENKINS_HOME/war/,
but since after 'Apr  9  2013' this is no more the case - last timestamp.

Update the folder manually at startup!