[IRCServices] Bug in NickServ listlinks

[Katarn]

Hi,

It was brought to my attention by a user the other day, that NickServ's
listlinks feature works for any nickname, without identifying for the
nick. By default, only services operators or above are supposed to be able
to do this I believe.
Basically, any person can come on with any nick that they want to see all
the linked nicks for, and use "/msg nickserv listlinks" to see all the
nicknames linked to that nick, if they have not identified at all.
-Katarn