Merge branch 'shortcuts-help' into 'master'

Fix help keyboard shortcut for relative URL setups

Fixes gitlab-org/gitlab-ce#12751

See merge request !3016

CHANGELOG

@@ -8,6 +8,7 @@ v 8.5.2
   - Fix broken icons on installations with relative URL (Artem Sidorenko)
   - Improve implementation to check read access to forks and add pagination
   - Don't show any "2FA required" message if it's not actually required
+  - Fix help keyboard shortcut on relative URL setups (Artem Sidorenko)
   - Update Rails to 4.2.5.2
 
 v 8.5.1

app/assets/javascripts/shortcuts.js.coffee

@@ -13,8 +13,10 @@ class @Shortcuts
     if $('#modal-shortcuts').length > 0
       $('#modal-shortcuts').modal('show')
     else
+      url = '/help/shortcuts'
+      url = gon.relative_url_root + url if gon.relative_url_root?
       $.ajax(
-        url: '/help/shortcuts',
+        url: url,
         dataType: 'script',
         success: (e) ->
           if location and location.length > 0