Downgrade gitlab-grack to 1.0.1 on a 6.4 installation

gistfile1.diff

% git diff
diff --git a/Gemfile b/Gemfile
index 2019cae..381869a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -33,7 +33,8 @@ gem 'omniauth-github'
 gem "gitlab_git", "~> 4.0.0.pre"
 
 # Ruby/Rack Git Smart-HTTP Server Handler
-gem 'gitlab-grack', '~> 2.0.0.pre', require: 'grack'
+#gem 'gitlab-grack', '~> 2.0.0.pre', require: 'grack'
+gem 'gitlab-grack', '~> 1.0.1', require: 'grack'
 
 # LDAP Auth
 gem 'gitlab_omniauth-ldap', '1.0.3', require: "omniauth-ldap"
diff --git a/Gemfile.lock b/Gemfile.lock
index 8aad7c8..3f8a8d3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -180,8 +180,8 @@ GEM
       nokogiri (~> 1.5.9)
       sanitize (~> 2.0.3)
       stringex (~> 1.5.1)
-    gitlab-grack (2.0.0.pre)
-      rack (~> 1.5.1)
+    gitlab-grack (1.0.1)
+      rack (~> 1.4.1)
     gitlab-grit (2.6.3)
       charlock_holmes (~> 0.6.9)
       diff-lcs (~> 1.1)
@@ -591,7 +591,7 @@ DEPENDENCIES
   github-markup (~> 0.7.4)
   gitlab-flowdock-git-hook (~> 0.4.2)
   gitlab-gollum-lib (~> 1.0.2)
-  gitlab-grack (~> 2.0.0.pre)
+  gitlab-grack (~> 1.0.1)
   gitlab-linguist (~> 2.9.6)
   gitlab-pygments.rb (~> 0.5.4)
   gitlab_git (~> 4.0.0.pre)