Ticket 47427 - Overflow in nsslapd-disk-monitoring-threshold

Bug Description:  Using ldapsearch shows threshold value as a negative number, even
                  though the feature is working correctly.

Fix Description:  When reading the dse, the server was trying to cast the value as a "int".
                  Changed CONFIG_INT to CONFIG_LONG for nsslapd-disk-monioring-threshold.

https://fedorahosted.org/389/ticket/47427

Reviewed by: richm(Thanks!)

ldap/servers/slapd/libglobs.c

@@ -1003,7 +1003,7 @@ static struct config_get_and_set {
 	{CONFIG_DISK_THRESHOLD, config_set_disk_threshold,
 		NULL, 0,
 		(void**)&global_slapdFrontendConfig.disk_threshold,
-		CONFIG_INT, (ConfigGetFunc)config_get_disk_threshold,
+		CONFIG_LONG, (ConfigGetFunc)config_get_disk_threshold,
 		DEFAULT_DISK_THRESHOLD},
 	{CONFIG_DISK_GRACE_PERIOD, config_set_disk_grace_period,
 		NULL, 0,