Bump sinatra from `cf1c6b1` to `a4dd24a`
Bump sinatra from `cf1c6b1` to `a4dd24a`

Bumps [sinatra](https://github.com/sinatra/sinatra) from `cf1c6b1` to `a4dd24a`.
- [Release notes](https://github.com/sinatra/sinatra/releases)
- [Commits](https://github.com/sinatra/sinatra/compare/cf1c6b156b30417b6998a94c941d675179fac7b0...a4dd24add24f2dd0e7299b9e68e12038138294d3)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
dwilkie/twilreapi,dwilkie/twilreapi