Add TODO

app/controllers/jwt_controller.rb

@@ -42,6 +42,9 @@ class JwtController < ApplicationController
   end
 
   def authenticate_user(login, password)
+    # TODO: this is a copy and paste from grack_auth,
+    # it should be refactored in the future
+
     user = Gitlab::Auth.new.find(login, password)
 
     # If the user authenticated successfully, we reset the auth failure count