vsftp 3.0 allows chrootUsers activation



Zentyal 3.4 ships a vsftp package that works again with the users chroot option so we are able to enable it again. I added anste tests to confirm it:

Zentyal FTP tests
    ConfigNetSetExternal: OK
    InstallFTP: OK
    EnableModules: OK
    AddUser: OK
    ConfigFTPNonSSLNonAnonymous: OK
    TestPut: OK
    TestGet: OK
    TestPwd: OK
    ConfigFTPNonSSLAnonymousReadWrite: OK
    TestPutAnonymous: OK
    TestGetAnonymous: OK
    ConfigFTPNonSSLAnonymousReadOnly: OK
    TestPutAnonymousReadOnly: OK
    TestGetAnonymousReadOnly: OK
    ConfigFTPNonSSLNonAnonymousWithChroot: OK
    TestPut: OK
    TestGet: OK
    TestPwd: OK
    check-zentyal-log: OK
    check-syslog-apparmor: OK