Fix bug where non-project members of the target project could set labels on new merge requests.

CHANGELOG

@@ -9,6 +9,7 @@ v 8.0.0 (unreleased)
   - Allow configuration of import sources for new projects (Artem Sidorenko)
 v 7.14.0 (unreleased)
+  - Fix bug where non-project members of the target project could set labels on new merge requests.
   - Update default robots.txt rules to disallow crawling of irrelevant pages (Ben Bodenmiller)
   - Fix redirection after sign in when using auto_sign_in_with_provider
   - Upgrade gitlab_git to 7.2.14 to ignore CRLFs in .gitmodules (Stan Hu)

app/views/shared/issuable/_form.html.haml

@@ -38,7 +38,7 @@
       .clearfix
       .error-alert
   %hr
-- if can?(current_user, :"admin_#{issuable.to_ability_name}", @project)
+- if can?(current_user, :"admin_#{issuable.to_ability_name}", issuable.project)
   .form-group
     .issue-assignee
       = f.label :assignee_id, class: 'control-label' do