Update last reindex bug

[spacemansteve]

During its periodic, cron-initiated reindex, master pipeline wants to process new records. So, retrieves the timestamp of when it last reindexed (which is stored in its postgres key/value table). As expected, this timestamp is used in a filter to generate a list of new bibcodes. However, the timestamp is also immediately updated. So if we fail to queue the bibcodes and then process them, they will be skipped during the next reindex. This happened when all the servers in SDC crashed on Jan 24 2019.