Change default worker model.

I (@alexander-pace) demonstrated this configuration change at the Penn State. I tested it on a VM at UWM and on gracedb-test on AWS and demonstrated failures are dropped to nearly zero for reasonable file sizes.

For "reasonable" file upload sizes, the number of failures is nearly zero. @chad-hanna indicated that gstlal's file uploads would nominally be 10mb.

I also demonstrated on AWS that this fix provides a minor performance increase.