Loader Subjob Query: Missing index

The 'subjob' query in the Loader/Daemon logs runs SQL with a "parent_job_name=" clause, but we did not have an index on parent_job_name.

Adding such an index made our grouper-log-listing 1000x faster when looking at subjobs.

CREATE INDEX ON grouper_loader_log (parent_job_name);

We also created an index on parent_job_id because it seemed more key'ish, but it's not clear that it'll be used by anything.