apps: remove the too big "Mirror a repository" header

fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/66445

app/views/projects/mirrors/_mirror_repos.html.haml

@@ -13,8 +13,6 @@
   .settings-content
     = form_for @project, url: project_mirror_path(@project), html: { class: 'gl-show-field-errors js-mirror-form', autocomplete: 'new-password', data: mirrors_form_data_attributes } do |f|
       .panel.panel-default
-        .panel-heading
-          %h3.panel-title= _('Mirror a repository')
         .panel-body
           %div= form_errors(@project)