Addition for the FAQ

[Paul Hoffman]

I hope this is the correct place to suggest document changes. I hit a
problem in setting up the rsyncd server last night, but finding the
problem was masked by the FAQ's "is your shell clean" answer. I
propose adding an additional paragraph to the response that says:

If the remote machine is running rsyncd (that is, if the client's
rsync command uses "::" instead of ":" after the remote machine name)
and you see the "is your shell clean" message, there is a good chance
that the configuration on the remote machine has errors in it. Have
the administrator of that machine look in the rsync logs for error
messages from the rsyncd server.