Use a more sane upper bound for S3 workers.
Use a more sane upper bound for S3 workers.

whd/data-pipeline,mozilla-services/data-pipeline,whd/data-pipeline,nathwill/data-pipeline,acmiyaguchi/data-pipeline,acmiyaguchi/data-pipeline,whd/data-pipeline,sapohl/data-pipeline,nathwill/data-pipeline,nathwill/data-pipeline,kparlante/data-pipeline,acmiyaguchi/data-pipeline,mozilla-services/data-pipeline,mozilla-services/data-pipeline,kparlante/data-pipeline,kparlante/data-pipeline,kparlante/data-pipeline,nathwill/data-pipeline,sapohl/data-pipeline,mozilla-services/data-pipeline,acmiyaguchi/data-pipeline,sapohl/data-pipeline,whd/data-pipeline,sapohl/data-pipeline