Fix problem with dosendpr.cgi hanging after a PR has been submitted
where no page was returned to the submitter resulting in many
duplicate PR's.

The pipe to sendmail was just being closed without the nice ".\n" to
tell sendmail this is the end of the mail. Now we always send "\n.\n"
to be sure the is a standalone "." on a line.

Why this wasn't a problem before, but is now, I'm not really sure, but
it's probably a perl 5.0 -> 5.8 change which triggered this.

If there are still problems after this commit, please report including
PR number(s).

Prodded by: bugmeister(s)
Co-prodding and testing help: edwin
Not fixed for far too long by: simon