Update cyrus-imapd24 to 2.4.4.

Changes to the Cyrus IMAP Server since 2.4.3

      * Rewrite index_upgrade to always parse the message files and
        re-create cyrus.cache, to avoid upgrade upgrade failures where
        cache errors occured.
      * Fixed sync_reset handling of user deletions
      * Fixed proc file handling of LOGIN and folder unselect
      * use cyrus.expunge file (if still present) to delete bogus records
        from a failed index upgrade (cause by bugs in earlier version)
      * detect version 2.5 in XFER to support use with master git branch in
        a murder
      * made pop3 expunge much more efficient
      * handle missing seen file in XFER

(obache)