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>

Gemfile.lock

@@ -96,7 +96,7 @@ GEM
     nio4r (2.5.2)
     nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
-    rack (2.2.2)
+    rack (2.2.3)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
     rails (6.0.3.1)