fixed bug: first job execution message is not displayed

the first job execution message (0-indexed) is not displayed when starting the job; it appears if you refresh the page
the problem was that /jobs/ID?msgSeq returns all messages *after* msgSeq but not *including* msgSeq.
fix for issue 302: Cancelled file uploads count negatively towards file count

The file count was subtracted twice; in both abortUpload and fileuploadfailed