nntpservers reports non-existing group fetch as a bogus command

If a sysop removes a group and a usenet client ties to fetch from it, it's logged as a bogus command and throttled, however each group after is also throttled. Fetching from a non-existent group should just be logged and skipped, especially for authenticated clients, since this then blocks further legitimate use.

Nov 30 22:42:04 bbs synchronet: srvc 0096 NNTP [Fidonet.OTHERNETS] cmd: XHDR cc 4275 Nov 30 22:42:04 bbs synchronet: srvc 0096 NNTP [Fidonet.OTHERNETS] cmd: GROUP Fidonet.R19_CHAT Nov 30 22:42:04 bbs synchronet: srvc 0096 NNTP [Fidonet.R19_CHAT] cmd: GROUP Fidonet.R19COORD Nov 30 22:42:04 bbs synchronet: srvc 0096 NNTP !no such group Nov 30 22:42:04 bbs synchronet: srvc 0096 NNTP Received bogus command: 'GROUP Fidonet.R19COORD' Nov 30 22:42:04 bbs synchronet: srvc 0096 NNTP Throttling bogus command sending client for 1 seconds Nov 30 22:42:06 bbs synchronet: srvc 0096 NNTP [Fidonet.R19SYSOP] cmd: GROUP Fidonet.SYSOP Nov 30 22:42:06 bbs synchronet: srvc 0096 NNTP Throttling bogus command sending client for 1 seconds

Obviously, this can only be fixed on the client side by the user removing the group but they may not be aware it's been removed.