Downgrade rack so logging in should work again in the steam web overlay

rack/rack#1603

Gemfile

@@ -39,6 +39,7 @@ gem 'omniauth-steam'
 gem 'paypal-sdk-rest'
 gem 'pg'
 gem 'puma'
+gem 'rack', '~> 2.1.4'
 gem 'rack-attack'
 gem 'rack-cache'
 gem 'rails', '~> 6.0.0'

Gemfile.lock

@@ -88,7 +88,7 @@ GEM
       sshkit (>= 1.6.1, != 1.7.0)
     american_date (1.1.1)
     ast (2.4.1)
-    autoprefixer-rails (9.8.6.2)
+    autoprefixer-rails (9.8.6.3)
       execjs
     backport (1.1.2)
     base32_pure (0.1.0)
@@ -290,7 +290,7 @@ GEM
     logs_tf (0.0.4)
       faraday (~> 0.8)
       multipart-post (>= 1.2.0)
-    loofah (2.6.0)
+    loofah (2.7.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.1)
@@ -350,7 +350,7 @@ GEM
       omniauth-openid
     orm_adapter (0.5.0)
     parallel (1.19.2)
-    parallel_tests (3.1.0)
+    parallel_tests (3.2.0)
       parallel
     parser (2.7.1.4)
       ast (~> 2.4.1)
@@ -373,7 +373,7 @@ GEM
     puma (4.3.5)
       nio4r (~> 2.0)
     raabro (1.3.1)
-    rack (2.2.3)
+    rack (2.1.4)
     rack-attack (6.3.1)
       rack (>= 1.0, < 3)
     rack-cache (1.12.0)
@@ -492,7 +492,7 @@ GEM
       tilt
     sentry-raven (2.13.0)
       faraday (>= 0.7.6, < 1.0)
-    shoulda-matchers (4.3.0)
+    shoulda-matchers (4.4.1)
       activesupport (>= 4.2.0)
     sidekiq (5.2.9)
       connection_pool (~> 2.2, >= 2.2.2)
@@ -534,7 +534,7 @@ GEM
     sshkit (1.21.0)
       net-scp (>= 1.1.2)
       net-ssh (>= 2.8.0)
-    stripe (5.23.1)
+    stripe (5.24.0)
     sync (0.5.0)
     sys-uname (1.2.1)
       ffi (>= 1.0.0)
@@ -645,6 +645,7 @@ DEPENDENCIES
   pg
   pry-nav
   puma
+  rack (~> 2.1.4)
   rack-attack
   rack-cache
   rails (~> 6.0.0)