Bump rack from 2.2.4 to 2.2.8 in /omnibus#5

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

dependabot/bundler/omnibus/rack-2.2.8ghasctl/inspec:dependabot/bundler/omnibus/rack-2.2.8Copy head branch name to clipboard