See <https://builds.apache.org/hudson/job/ftpserver-trunk-jdk1.6-osx/org.apache.ftpserver$ftpserver-core/28/changes>
- Jenkins build became unstable: ftpserver-trunk-jdk1... Apache Jenkins Server
- Jenkins build is still unstable: ftpserver-trun... Apache Jenkins Server
- Jenkins build is back to stable : ftpserver... Apache Jenkins Server