(#787434) modify group of /var/run/clamd.scan
    
    After 6 years and reading some reports as bug #787434, #1284253, we need
    that /var/run/clamd.scan can be read from oher users, changing directory
    ownerchip to virusgroup, makes clamilt and users of virusgroup group,
    access to directory and read the socket.
    This solution also assure that regular user don't have access to the
    directory .