Bugzilla Bug 605 fun fixed

[Daniel Berlin]

For those who don't know, someone using a challenge response system 
unknowingly (presumably, since he never got the emails, since they 
never made it through!) caused 194 comments to be appended to a bug 
over the course of the past 1 hour, because it decided to reply to a 
gcc-bugs email.
It also caused 194 messages to gcc-bugs as a result of adding these 
comments.
So I disabled his bugzilla account, and changed bugzilla_email_append 
not to append comments from disabled users.

This is also serving as fair warning to anyone using these challenge 
response systems:
Please either make sure they let through gcc-bugs mail, or aren't 
stupid enough to respond to the sender of list mails.

I've copied overseers so you guys know this is taken care of.
You may want to hand-remove the 194 messages from the list archives so 
they don't pollute it, if easily possible.

--Dan