Add active users to gitlab:check

lib/tasks/gitlab/check.rake

@@ -29,6 +29,7 @@ namespace :gitlab do
       check_redis_version
       check_ruby_version
       check_git_version
+      check_active_users
       finished_checking "GitLab"
     end
@@ -781,6 +782,10 @@ namespace :gitlab do
     end
   end
+  def check_active_users
+    puts "Active users: #{User.active.count}"
+  end
+
   def omnibus_gitlab?
     Dir.pwd == '/opt/gitlab/embedded/service/gitlab-rails'
   end