Make sure generated Jenkins jobs running integration tests update relevant Jira issues

Script at nuxeo-studio/jenkins/nuxeo-studio-itests-seed.dsl.groovy is in charge of generating Jenkins jobs that will run functional tests.

When making changes to the branches holding the tests, the corresponding Jira issue is not updated because jobs are missing the configuration for this plugin.

Doc at https://github.com/jenkinsci/job-dsl-plugin/wiki/The-Configure-Block gives some post build samples to take example on, the id to use to setup usage of this plugin seems to be "hudson.plugins.jira.JiraIssueUpdater".