Remove save button for managed repositories

This commit removes the settings `save` button for managed repositories.

Important: When adjustable settings for any vendor should be added,
this button must be shown depending on some individual vendor logic.

app/views/repositories/_settings.html.erb

@@ -54,7 +54,11 @@ See doc/COPYRIGHT.rdoc for more details.
   <% unless @repository.nil? %>
       <%= render partial: "/repositories/settings/vendor_form",
                  locals: { form: f, repository: @repository, vendor: vendor_name(@repository) } %>
-      <%= render partial: "/repositories/settings/submit",
+
-                 locals: { form: f, is_creation_form: is_creation_form, project: @project } %>
+      <%# Hide the save button for existing managed repositories %>
+      <% if is_creation_form || !@repository.managed? %>
+        <%= render partial: "/repositories/settings/submit",
+                   locals: { form: f, is_creation_form: is_creation_form, project: @project } %>
+      <% end %>
   <% end %>
 <% end %>

spec/features/repositories/create_repository_spec.rb

@@ -140,7 +140,7 @@ describe 'Create repository', type: :feature, js: true do
         find('input[type="radio"][value="managed"]').set(true)
         find('button[type="submit"]', text: I18n.t(:button_create)).click
 
-        expect(page).to have_selector('button', text: I18n.t(:button_save))
+        expect(page).not_to have_selector('button', text: I18n.t(:button_save))
         expect(page).to have_selector('a.icon-delete', text: I18n.t(:button_delete))
       end
     end