Bump rack from 2.2.2 to 2.2.3

Bumps [rack](https://github.com/rack/rack) from 2.2.2 to 2.2.3.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/master/CHANGELOG.md)
- [Commits](rack/rack@v2.2.2...2.2.3)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -110,7 +110,7 @@ GEM
     pg (1.2.3)
     puma (4.3.3)
       nio4r (~> 2.0)
-    rack (2.2.2)
+    rack (2.2.3)
     rack-proxy (0.6.5)
       rack
     rack-test (1.1.0)