Bump rack from 2.2.4 to 2.2.8.1 in /omnibus#6

dependabot[bot] wants to merge 1 commit intomainghasctl/inspec:mainfrom

dependabot/bundler/omnibus/rack-2.2.8.1ghasctl/inspec:dependabot/bundler/omnibus/rack-2.2.8.1Copy head branch name to clipboard