hacker.js: remove unecessary `string_server_used` parameter for `exec` used in `void_schedule_runner`.

Created by  jesse <nicoty@tuta.io>  on April 29, 2020
6CV2IKC2HYT6YTQU3RQKPZSH3BRFPDGLHTU3LF7D66SO2GCVNQWAC
Change contents