off by one when checking ISO2ASC

here's a fix for a crash with "ISO2ASC=7 tin"

=== modified file 'src/init.c'
--- src/init.c	2013-03-05 12:52:55 +0000
+++ src/init.c	2013-08-27 12:59:00 +0000
@@ -695,7 +695,7 @@
 	disable_gnksa_domain_check = FALSE;
 	disable_sender = FALSE;	/* we set force_no_post=TRUE later on if we don't have a valid FQDN */
 	iso2asc_supported = atoi(get_val("ISO2ASC", DEFAULT_ISO2ASC));
-	if (iso2asc_supported > NUM_ISO_TABLES || iso2asc_supported < 0) /* TODO: issue a warning here? */
+	if (iso2asc_supported >= NUM_ISO_TABLES || iso2asc_supported < 0) /* TODO: issue a warning here? */
 		iso2asc_supported = -1;
 	list_active = FALSE;
 	newsrc_active = FALSE;