Remove duplicate contribute to gitlab link

app/views/layouts/header/_current_user_dropdown.html.haml

@@ -32,7 +32,8 @@
   %li.d-md-none
     = link_to _("Submit feedback"), "https://about.gitlab.com/submit-feedback"
   - if current_user_menu?(:help) || current_user_menu?(:settings) || current_user_menu?(:profile)
-    = render 'shared/user_dropdown_contributing_link'
+    %li.d-md-none
+      = render 'shared/user_dropdown_contributing_link'
   = render_if_exists 'shared/user_dropdown_instance_review'
   - if Gitlab.com?
     %li.js-canary-link.d-md-none

app/views/layouts/header/_help_dropdown.html.haml

@@ -9,7 +9,8 @@
   %li
     = link_to _("Submit feedback"), "https://about.gitlab.com/submit-feedback"
   - if current_user_menu?(:help) || current_user_menu?(:settings) || current_user_menu?(:profile)
-    = render 'shared/user_dropdown_contributing_link'
+    %li
+      = render 'shared/user_dropdown_contributing_link'
   = render_if_exists 'shared/user_dropdown_instance_review'
   - if Gitlab.com?
     %li.js-canary-link

app/views/shared/_user_dropdown_contributing_link.html.haml

-%li
-  = link_to "https://about.gitlab.com/contributing", target: '_blank', class: 'text-nowrap' do
-    = _("Contribute to GitLab")
+= link_to "https://about.gitlab.com/contributing", target: '_blank', class: 'text-nowrap' do
+  = _("Contribute to GitLab")