Allow +z messages from outside if -n.

This gives a useful meaning to the cmode combo +mz-n:
messages from ops and voices go to all channel members,
messages from anyone else (on or off channel) go to ops.
With +mnz, messages from outside are not allowed at all.

modules/core/m_message.c

@@ -477,7 +477,8 @@ msg_channel(int p_or_n, const char *command,
 	}
 	else if(chptr->mode.mode & MODE_OPMODERATE &&
 			chptr->mode.mode & MODE_MODERATED &&
-			IsMember(source_p, chptr))
+			(!(chptr->mode.mode & MODE_NOPRIVMSGS) ||
+			 IsMember(source_p, chptr)))
 	{
 		/* only do +z for +m channels for now, as bans/quiets
 		 * aren't tested for remote clients -- jilles */