Resolve post-checkout hook issue with pot generation

- failures happen when bundle install is ran on
  post checkout hook.

lib/tasks/gettext.rake

@@ -38,7 +38,7 @@ namespace :gettext do
     Rake::Task['gettext:find'].invoke
 
     # leave only the required changes.
-    unless system(*%w(git checkout -- locale/*/gitlab.po))
+    unless system(*%w(git -c core.hooksPath=/dev/null checkout -- locale/*/gitlab.po))
       raise 'failed to cleanup generated locale/*/gitlab.po files'
     end