update for ftp-upload script documentation

[Ward Vandewege]

Currently,

  http://www.gnu.org/prep/maintain/maintain.html#Automated-Upload-Procedure

says:

"Uploads are processed every five minutes. Uploads that are in progress
while the upload processing script is running are handled properly, so
do not worry about the timing of your upload."

This should be added (same paragraph):

"Uploaded files that belong to an incomplete triplet will be deleted
automatically after 24 hours."

This will help people who have trouble uploading when old files are in the
way.

Thanks,
Ward.

-- 
Ward Vandewege <address@hidden>
Free Software Foundation - Senior System Administrator