Bump gitlab-shell to 1.7.4 (CVE-2013-4490)

doc/install/installation.md

@@ -119,7 +119,7 @@ GitLab Shell is a ssh access and repository management software developed specia
     cd gitlab-shell
 
     # switch to right version
-    sudo -u git -H git checkout v1.5.0
+    sudo -u git -H git checkout v1.7.4
 
     sudo -u git -H cp config.yml.example config.yml
 

lib/tasks/gitlab/check.rake

@@ -657,7 +657,7 @@ namespace :gitlab do
   end
 
   def check_gitlab_shell
-    required_version = Gitlab::VersionInfo.new(1, 4, 0)
+    required_version = Gitlab::VersionInfo.new(1, 7, 4)
     current_version = Gitlab::VersionInfo.parse(gitlab_shell_version)
 
     print "GitLab Shell version >= #{required_version} ? ... "