fix setting gon.api_token

app/controllers/application_controller.rb

@@ -152,7 +152,9 @@ class ApplicationController < ActionController::Base
 
   def add_gon_variables
     gon.default_issues_tracker = Project.issues_tracker.default_value
+    if current_user
       gon.api_token = current_user.private_token
       gon.gravatar_url = request.ssl? ? Gitlab.config.gravatar.ssl_url : Gitlab.config.gravatar.plain_url
     end
+  end
 end