Bump rack-attack from 6.1.0 to 6.2.1 (#12421)

Bumps [rack-attack](https://github.com/kickstarter/rack-attack) from 6.1.0 to 6.2.1.
- [Release notes](https://github.com/kickstarter/rack-attack/releases)
- [Changelog](https://github.com/kickstarter/rack-attack/blob/master/CHANGELOG.md)
- [Commits](https://github.com/kickstarter/rack-attack/compare/v6.1.0...v6.2.1)

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

Gemfile

@@ -71,7 +71,7 @@ gem 'parallel', '~> 1.18'
 gem 'posix-spawn', git: 'https://github.com/rtomayko/posix-spawn', ref: '58465d2e213991f8afb13b984854a49fcdcc980c'
 gem 'pundit', '~> 2.1'
 gem 'premailer-rails'
-gem 'rack-attack', '~> 6.1'
+gem 'rack-attack', '~> 6.2'
 gem 'rack-cors', '~> 1.0', require: 'rack/cors'
 gem 'rails-i18n', '~> 5.1'
 gem 'rails-settings-cached', '~> 0.6'

Gemfile.lock

@@ -459,7 +459,7 @@ GEM
       activesupport (>= 3.0.0)
     raabro (1.1.6)
     rack (2.0.7)
-    rack-attack (6.1.0)
+    rack-attack (6.2.1)
       rack (>= 1.0, < 3)
     rack-cors (1.0.6)
       rack (>= 1.6.0)
@@ -765,7 +765,7 @@ DEPENDENCIES
   pry-rails (~> 0.3)
   puma (~> 4.2)
   pundit (~> 2.1)
-  rack-attack (~> 6.1)
+  rack-attack (~> 6.2)
   rack-cors (~> 1.0)
   rails (~> 5.2.3)
   rails-controller-testing (~> 1.0)