TICKET_ADMIN should permit editing of reporter field

[trac@…]

15:04  sabi> so, you can't edit the 'reporter' field in tickets?
15:05  cmlenz> sabi, why'd you want to?
15:06  sabi> cmlenz: if i'm posting something on behalf of someone else
15:06  sabi> most users don't create their own trac tickets here, they send
             email to us and we reformat/post them.
15:06  sabi> this time i forgot to change the field before i posted it...
15:07  sabi> i'll just file a ticket. :)
15:07  cmlenz> that would be similar to editing the description if you have
               TICKET_ADMIN perms, I think

[daniel]

Fixed in [822].