causes duplicate upgrade_log_pkey error

[StephenGWills]

The upgrade script Open-ILS/src/sql/Pg/1.6.1.4-1.6.1.5-upgrade-db.sql in Evergreen-ILS-1.6.1.8 contains the line:
- INSERT INTO config.upgrade_log(version) VALUES ('1.6.1.4');
instead of:
+ INSERT INTO config.upgrade_log(version) VALUES ('1.6.1.5');

[StephenGWills (swills)]

fairly low priority but when running the upgrade path, makesone have to stop and investigate.

[Galen Charlton (gmc)]

Thanks. I've pushed a fix for when 1.6.1.9 is released.