src/s_conf: Moved error notification to proper place

Previously it was in src/ircd.c, but accroding to jilles, this is a better place for the notification.

This changes a patch made in adef4da10c65696fb9b79ffa797615770fd53abf and amended in 65d921173c6e3aa4f30dd78561d3a6f5d5f4cf31 and f6f049070e240d0ce637e9e3ac4fba4148b9725d.