Fix tests and improve wording

app/views/groups/show.html.haml

@@ -37,5 +37,4 @@
         = render "projects", projects: @projects
   - else
     %p
-      = icon('lock')
-      This is a private group
+      This group does not have public projects

spec/controllers/namespaces_controller_spec.rb

@@ -84,10 +84,10 @@ describe NamespacesController do
           end
 
           context "when the user doesn't have access to the project" do
-            it "responds with status 404" do
+            it "redirects to the group's page" do
               get :show, id: group.path
 
-              expect(response.status).to eq(404)
+              expect(response).to redirect_to(group_path(group))
             end
           end
         end