daupload errors if you tell it to go on in spite of files missing

[broder]

daupload tests for missing files, and prompts you for if you want to continue the upload. If you say yes, though, it will error when it hits the first missing files.

In my particular case, this resulted in the new source package being uploaded to all releases, but the binary packages for Gutsy, Hardy, and Intrepid weren't uploaded.