Use rugged to change HEAD

CHANGELOG

@@ -32,6 +32,7 @@ v 8.7.0 (unreleased)
   - Add default scope to projects to exclude projects pending deletion
   - Allow to close merge requests which source projects(forks) are deleted.
   - Ensure empty recipients are rejected in BuildsEmailService
+  - Use rugged to change HEAD in Project#change_head (P.S.V.R)
   - API: Ability to filter milestones by state `active` and `closed` (Robert Schilling)
   - API: Fix milestone filtering by `iid` (Robert Schilling)
   - API: Delete notes of issues, snippets, and merge requests (Robert Schilling)

app/models/project.rb

@@ -865,7 +865,9 @@ class Project < ActiveRecord::Base
 
   def change_head(branch)
     repository.before_change_head
-    gitlab_shell.update_repository_head(self.path_with_namespace, branch)
+    repository.rugged.references.create('HEAD',
+                                        "refs/heads/#{branch}",
+                                        force: true)
     reload_default_branch
   end