iad2: disable fedmsg/base role on bodhi-backend01.iad2 for now
    
    There's only one script using it left and perhaps we can port or fix
    that. python3 ansible on new batcave01.iad does not like this use of
    sort in the fedmsg filter, it says:
    
    AttributeError: 'dict_items' object has no attribute 'sort'"
    
    Signed-off-by: Kevin Fenzi <kevin@scrye.com>