Add the /var/cache/swift bz#870409
    
    Not having the recon directory is generally harmless, but
    1. it produces tracebacks into logs
    2. someone is likely to use recon and will create it anyway
    
    I don't see a downside and ownding directories in /var/cache
    appears to be permitted.
    
    Since recon cache is overwritten on each dump, we could locate
    this in /var/run (/run), but I'm not quite sure if it's worth
    the bother and surprise. No, I don't know exactly why Debian
    chose /var/cache. Possibly deceived by the word "cache" in the
    phrase "recon cache".
    
    See bz#870409.