Merge branch 'external-wiki-helper-speedup' into 'master'

speed up ExternalWikiService#get_project_wiki_path

## What does this MR do?

Speed up ExternalWikiHelper#get_project_wiki_path

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

See issue #19886 

## What are the relevant issue numbers?

#19886 

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5305

1 files changed, 7 insertions, 0 deletions

diff --git a/db/migrate/20160718153603_add_has_external_wiki_to_projects.rb b/db/migrate/20160718153603_add_has_external_wiki_to_projects.rb
new file mode 100644
index 00000000000..55a3e954292
--- /dev/null
+++ b/db/migrate/20160718153603_add_has_external_wiki_to_projects.rb
@@ -0,0 +1,7 @@
+class AddHasExternalWikiToProjects < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  def change
+    add_column :projects, :has_external_wiki, :boolean
+  end
+end