gnupload example

[Karl Berry]

gnupload --help has this example:

  gnupload ...
           --to alpha.gnu.org:automake \\
           ...

I suggest changing it to:
           --to alpha.gnu.org:gnu/automake \\

Otherwise, there is a possible confusion that gnupload puts in the
"gnu/" for you.  (This confused me for a while, silly me.)

Thanks,
Karl